Update dependency next to v15.5.21 [SECURITY] by renovate[bot] · Pull Request #580 · diffplug/selfie

renovate · 2026-07-27T14:53:27Z

This PR contains the following updates:

Package	Change	Age	Confidence
next (source)	`15.5.18` → `15.5.21`

Next.js: Denial of Service in the Image Optimization API using SVGs

CVE-2026-64644 / GHSA-q8wf-6r8g-63ch

More information

Details

Impact

When self-hosting Next.js with the default image loader, the Image Optimization API can optimize remotely hosted images if configured (not enabled by default). If those images contain malicious content, they can cause CPU exhaustion in /_next/image endpoints.

If you are using config.images.remotePatterns, only the patterns in that array are impacted.
If you are using config.images.unoptimized: true, you are NOT impacted.
If you are using config.images.loader: 'custom', you are NOT impacted.
If you are using Vercel, you are NOT impacted.

Workarounds

If you cannot upgrade immediately, you can avoid the expensive work by setting config.experimental.imgOptSkipMetadata : true.

Severity

CVSS Score: 6.3 / 10 (Medium)
Vector String: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

Next.js: Server-Side Request Forgery in Server Actions on custom servers

CVE-2026-64649 / GHSA-89xv-2m56-2m9x

More information

Details

Impact

When a Server Action forwards or redirects a request, an attacker can cause the server to send that outbound request to a malicious host (Server-Side Request Forgery). This requires the attacker's request to control Host-associated headers. In some configurations, it's also possible to obtain internal values that weaken middleware/proxy authorization.

Applications that use Server Actions are affected when the incoming host header is not fixed to a trusted value. This typically occurs on custom servers, or on deployments not behind a proxy that pins the host. Managed hosting pins the host upstream and is not affected; next start and standalone output do the same from version 14.2 onward.

Workarounds

If you cannot upgrade, ensure clients do not control the host header your application receives. Pin or validate Host and X-Forwarded-Host at your edge or proxy. On version 14.2.0 and later, you can additionally set the __NEXT_PRIVATE_ORIGIN environment variable to your deployment's real origin:

__NEXT_PRIVATE_ORIGIN=https://www.example.com node server.js

#### Severity
- CVSS Score: 8.3 / 10 (High)
- Vector String: `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N`

#### References
- [https://github.com/vercel/next.js/security/advisories/GHSA-89xv-2m56-2m9x](https://redirect.github.com/vercel/next.js/security/advisories/GHSA-89xv-2m56-2m9x)
- [https://github.com/vercel/next.js/commit/b51206321854193208c0805ba42acc49287f942b](https://redirect.github.com/vercel/next.js/commit/b51206321854193208c0805ba42acc49287f942b)
- [https://github.com/vercel/next.js/commit/e3e5666ccead3a15162793d697af5e48b7cc0498](https://redirect.github.com/vercel/next.js/commit/e3e5666ccead3a15162793d697af5e48b7cc0498)
- [https://github.com/vercel/next.js/releases/tag/v15.5.21](https://redirect.github.com/vercel/next.js/releases/tag/v15.5.21)
- [https://github.com/vercel/next.js/releases/tag/v16.2.11](https://redirect.github.com/vercel/next.js/releases/tag/v16.2.11)
- [https://github.com/advisories/GHSA-89xv-2m56-2m9x](https://redirect.github.com/advisories/GHSA-89xv-2m56-2m9x)

This data is provided by the [GitHub Advisory Database](https://redirect.github.com/advisories/GHSA-89xv-2m56-2m9x) ([CC-BY 4.0](https://redirect.github.com/github/advisory-database/blob/main/LICENSE.md)).
</details>

---

### Next.js: Cache confusion of response bodies for requests with bodies containing invalid UTF-8 byte sequences
[CVE-2026-64647](https://nvd.nist.gov/vuln/detail/CVE-2026-64647) / [GHSA-4633-3j49-mh5q](https://redirect.github.com/advisories/GHSA-4633-3j49-mh5q)

<details>
<summary>More information</summary>

#### Details
##### Impact

A server-side `fetch` with a request body may return a cached **response** body from a different request to the same URL but different body. Confidential data in the `POST`'s **response** body would then leak to unauthorized requests. Though the request itself will not be deduped.

This is only an issue when receiving request bodies with a content type charset other than UTF-8. For example, the UTF-16 byte sequences for `삃삃` and `섄섄` in the request body would share the same cache.

##### Workarounds

If you cannot upgrade, consider only making fetch requests with UTF-8 bodies (default in Next.js). Applications using Pages Router are not vulnerable.

#### Severity
- CVSS Score: 6.3 / 10 (Medium)
- Vector String: `CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`

#### References
- [https://github.com/vercel/next.js/security/advisories/GHSA-4633-3j49-mh5q](https://redirect.github.com/vercel/next.js/security/advisories/GHSA-4633-3j49-mh5q)
- [https://github.com/vercel/next.js/pull/96008](https://redirect.github.com/vercel/next.js/pull/96008)
- [https://github.com/vercel/next.js/commit/025bf4a5f7b47fb7758c4ebf1c931a61c451c082](https://redirect.github.com/vercel/next.js/commit/025bf4a5f7b47fb7758c4ebf1c931a61c451c082)
- [https://github.com/vercel/next.js/releases/tag/v15.5.21](https://redirect.github.com/vercel/next.js/releases/tag/v15.5.21)
- [https://github.com/vercel/next.js/releases/tag/v16.2.11](https://redirect.github.com/vercel/next.js/releases/tag/v16.2.11)
- [https://github.com/advisories/GHSA-4633-3j49-mh5q](https://redirect.github.com/advisories/GHSA-4633-3j49-mh5q)

This data is provided by the [GitHub Advisory Database](https://redirect.github.com/advisories/GHSA-4633-3j49-mh5q) ([CC-BY 4.0](https://redirect.github.com/github/advisory-database/blob/main/LICENSE.md)).
</details>

---

### Next.js: Cache confusion of response bodies for requests with bodies
[CVE-2026-64648](https://nvd.nist.gov/vuln/detail/CVE-2026-64648) / [GHSA-68g3-v927-f742](https://redirect.github.com/advisories/GHSA-68g3-v927-f742)

<details>
<summary>More information</summary>

#### Details
##### Impact

A server-side `fetch` with a request body may return a cached **response** body from a different request to the same URL but different body. Confidential data in the `POST`'s **response** body would then leak to unauthorized requests. Though the request itself will not be deduped.

This only applies to `fetch` calls with a request that has a different init than the one passed to `fetch`.
Safe: `fetch(new Request(init), init)`
Unsafe: `fetch(new Request(init), aDifferentInit)`

##### Workarounds

No workaround exists besides upgrading. Applications using Pages Router are not vulnerable.

#### Severity
- CVSS Score: 6.0 / 10 (Medium)
- Vector String: `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N`

#### References
- [https://github.com/vercel/next.js/security/advisories/GHSA-68g3-v927-f742](https://redirect.github.com/vercel/next.js/security/advisories/GHSA-68g3-v927-f742)
- [https://github.com/vercel/next.js/commit/062f66700b52a5d6bba2c0605d55577ab7ad262c](https://redirect.github.com/vercel/next.js/commit/062f66700b52a5d6bba2c0605d55577ab7ad262c)
- [https://github.com/vercel/next.js/commit/73b94872bc343d09494b50394d8c08eb9fc8e56a](https://redirect.github.com/vercel/next.js/commit/73b94872bc343d09494b50394d8c08eb9fc8e56a)
- [https://github.com/vercel/next.js/releases/tag/v15.5.21](https://redirect.github.com/vercel/next.js/releases/tag/v15.5.21)
- [https://github.com/vercel/next.js/releases/tag/v16.2.11](https://redirect.github.com/vercel/next.js/releases/tag/v16.2.11)
- [https://github.com/advisories/GHSA-68g3-v927-f742](https://redirect.github.com/advisories/GHSA-68g3-v927-f742)

This data is provided by the [GitHub Advisory Database](https://redirect.github.com/advisories/GHSA-68g3-v927-f742) ([CC-BY 4.0](https://redirect.github.com/github/advisory-database/blob/main/LICENSE.md)).
</details>

---

### Next.js: Unauthenticated disclosure of internal Server Function endpoints
[CVE-2026-64643](https://nvd.nist.gov/vuln/detail/CVE-2026-64643) / [GHSA-955p-x3mx-jcvp](https://redirect.github.com/advisories/GHSA-955p-x3mx-jcvp)

<details>
<summary>More information</summary>

#### Details
##### Impact

In Next.js applications using App Router, Server Actions (`use server`) or `use cache` endpoints can be disclosed bypassing any authentication on the pages where these endpoints are usually used.

Server Action IDs can be disclosed to unauthenticated users via publicly served client artifacts (for example, static chunks containing action references).

Affected users are applications using App Router + Server Actions.  

By itself, this disclosure is typically a recon/enumeration primitive; however, it can increase risk when combined with other weaknesses.
 

##### Workarounds

Never assume any authentication claims at the `use cache` or `use server` boundary. Always authenticate within the boundary.

#### Severity
- CVSS Score: 6.3 / 10 (Medium)
- Vector String: `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`

#### References
- [https://github.com/vercel/next.js/security/advisories/GHSA-955p-x3mx-jcvp](https://redirect.github.com/vercel/next.js/security/advisories/GHSA-955p-x3mx-jcvp)
- [https://github.com/vercel/next.js/commit/1b0c3ae912a3ad925c60065cc8d55b070fa8bcd3](https://redirect.github.com/vercel/next.js/commit/1b0c3ae912a3ad925c60065cc8d55b070fa8bcd3)
- [https://github.com/vercel/next.js/commit/ff12a6124e1504f17b62de948b8a553fdecaef7b](https://redirect.github.com/vercel/next.js/commit/ff12a6124e1504f17b62de948b8a553fdecaef7b)
- [https://github.com/vercel/next.js/releases/tag/v15.5.21](https://redirect.github.com/vercel/next.js/releases/tag/v15.5.21)
- [https://github.com/vercel/next.js/releases/tag/v16.2.11](https://redirect.github.com/vercel/next.js/releases/tag/v16.2.11)
- [https://github.com/advisories/GHSA-955p-x3mx-jcvp](https://redirect.github.com/advisories/GHSA-955p-x3mx-jcvp)

This data is provided by the [GitHub Advisory Database](https://redirect.github.com/advisories/GHSA-955p-x3mx-jcvp) ([CC-BY 4.0](https://redirect.github.com/github/advisory-database/blob/main/LICENSE.md)).
</details>

---

### Next.js: Denial of Service in App Router using Server Actions
[CVE-2026-64641](https://nvd.nist.gov/vuln/detail/CVE-2026-64641) / [GHSA-m99w-x7hq-7vfj](https://redirect.github.com/advisories/GHSA-m99w-x7hq-7vfj)

<details>
<summary>More information</summary>

#### Details
##### Impact

Crafted requests targeting Next.js applications using App Router with at least one Server Action can lead to excessive CPU usage blocking processing of further requests in the same process.

##### Workarounds

No workaround exists besides upgrading. Applications using Pages Router or not using Server Actions are not vulnerable.

#### Severity
- CVSS Score: 8.2 / 10 (High)
- Vector String: `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`

#### References
- [https://github.com/vercel/next.js/security/advisories/GHSA-m99w-x7hq-7vfj](https://redirect.github.com/vercel/next.js/security/advisories/GHSA-m99w-x7hq-7vfj)
- [https://github.com/vercel/next.js/pull/96013](https://redirect.github.com/vercel/next.js/pull/96013)
- [https://github.com/vercel/next.js/commit/019628571641dec57aaf349ba0c360e3964e6f12](https://redirect.github.com/vercel/next.js/commit/019628571641dec57aaf349ba0c360e3964e6f12)
- [https://github.com/vercel/next.js/releases/tag/v15.5.21](https://redirect.github.com/vercel/next.js/releases/tag/v15.5.21)
- [https://github.com/vercel/next.js/releases/tag/v16.2.11](https://redirect.github.com/vercel/next.js/releases/tag/v16.2.11)
- [https://github.com/advisories/GHSA-m99w-x7hq-7vfj](https://redirect.github.com/advisories/GHSA-m99w-x7hq-7vfj)

This data is provided by the [GitHub Advisory Database](https://redirect.github.com/advisories/GHSA-m99w-x7hq-7vfj) ([CC-BY 4.0](https://redirect.github.com/github/advisory-database/blob/main/LICENSE.md)).
</details>

---

### Next.js: Unbounded Server Action payload in Edge runtime
[CVE-2026-64646](https://nvd.nist.gov/vuln/detail/CVE-2026-64646) / [GHSA-4c39-4ccg-62r3](https://redirect.github.com/advisories/GHSA-4c39-4ccg-62r3)

<details>
<summary>More information</summary>

#### Details
##### Impact

Requests targeting Next.js applications using App Router with at least one Server Action can lead to excessive memory consumption if that Server Actions uses the Edge runtime

##### Workarounds

If you cannot upgrade, ensure your hosting provider limits the request's body size. 5 MiB should be allowed at max by your hosting provider.

#### Severity
- CVSS Score: 6.3 / 10 (Medium)
- Vector String: `CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N`

#### References
- [https://github.com/vercel/next.js/security/advisories/GHSA-4c39-4ccg-62r3](https://redirect.github.com/vercel/next.js/security/advisories/GHSA-4c39-4ccg-62r3)
- [https://github.com/vercel/next.js/commit/57c31f724d746e86a9e8b92aa8be538a922446a4](https://redirect.github.com/vercel/next.js/commit/57c31f724d746e86a9e8b92aa8be538a922446a4)
- [https://github.com/vercel/next.js/commit/9a4651e754f70b12e397694ffc41f44c3ba8cc17](https://redirect.github.com/vercel/next.js/commit/9a4651e754f70b12e397694ffc41f44c3ba8cc17)
- [https://github.com/vercel/next.js/releases/tag/v15.5.21](https://redirect.github.com/vercel/next.js/releases/tag/v15.5.21)
- [https://github.com/vercel/next.js/releases/tag/v16.2.11](https://redirect.github.com/vercel/next.js/releases/tag/v16.2.11)
- [https://github.com/advisories/GHSA-4c39-4ccg-62r3](https://redirect.github.com/advisories/GHSA-4c39-4ccg-62r3)

This data is provided by the [GitHub Advisory Database](https://redirect.github.com/advisories/GHSA-4c39-4ccg-62r3) ([CC-BY 4.0](https://redirect.github.com/github/advisory-database/blob/main/LICENSE.md)).
</details>

---

### Next.js: Server-Side Request Forgery in rewrites via attacker-controlled destination hostname
[CVE-2026-64645](https://nvd.nist.gov/vuln/detail/CVE-2026-64645) / [GHSA-p9j2-gv94-2wf4](https://redirect.github.com/advisories/GHSA-p9j2-gv94-2wf4)

<details>
<summary>More information</summary>

#### Details
##### Impact

A `rewrites()` or `redirects()` rule that builds its external destination hostname from request-controlled input can be pointed at an arbitrary hostname, regardless of the rule's hostname suffix. For a rewrite, Next.js proxies the request to that arbitrary host and serves the response from the application's origin, leading to Server-Side Request forgery. A `redirects()` rule configured this way is vulnerable to an Open Redirect.

This affects any destination that puts a dynamic segment in the hostname, whether from the path:

```javascript
// next.config.js
module.exports = {
  async rewrites() {
    return [
      {
        source: '/:tenant',
        destination: 'https://:tenant.api.example.com',
      },
    ]
  },
}

or from a has capture:

// next.config.js
module.exports = {
  async rewrites() {
    return [
      {
        source: '/',
        has: [{ type: 'query', key: 'region', value: '(?<region>.+)' }],
        destination: 'https://:region.api.example.com',
      },
    ]
  },
}

Workarounds

If you cannot upgrade immediately, do not build the hostname of an external rewrites() or redirects() destination from user-controlled input. If a dynamic subdomain is required, constrain the value to hostname-safe characters: value: '(?<region>[a-z0-9-]+)'.

Severity

CVSS Score: 8.3 / 10 (High)
Vector String: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:L/SI:L/SA:N

References

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

Release Notes

vercel/next.js (next)

`v15.5.21`

Compare Source

`v15.5.20`

Compare Source

Contains no changes except publishing @next/swc-wasm-web which was accidentally not published since 15.5.15.

`v15.5.19`: 15.5.19

Compare Source

[!NOTE]
This release is backporting bug fixes. It does not include all pending features/changes on canary.

Core Changes

[15.5.x] Don't drop FormData entries (#94244)

Other

[15.5.x] Fix CI (#94281)

Credits

Huge thanks to @eps1lon for helping!

Configuration

📅 Schedule: (UTC)

Branch creation
- At any time (no schedule defined)
Automerge
- At any time (no schedule defined)

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

If you want to rebase/retry this PR, check this box

This PR was generated by Mend Renovate. View the repository job log.

cloudflare-workers-and-pages · 2026-07-27T14:55:11Z

Deploying selfie with Cloudflare Pages

Latest commit:	`3264f55`
Status:	✅ Deploy successful!
Preview URL:	https://d5f80408.selfie-4ye.pages.dev
Branch Preview URL:	https://renovate-npm-next-vulnerabil.selfie-4ye.pages.dev

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Update dependency next to v15.5.21 [SECURITY]

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renovate Bot added the docs Improvements or additions to documentation label Jul 27, 2026

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Update dependency next to v15.5.21 [SECURITY] - #580

Update dependency next to v15.5.21 [SECURITY]#580
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Next.js: Denial of Service in the Image Optimization API using SVGs

Details

Impact

Workarounds

Severity

References

Next.js: Server-Side Request Forgery in Server Actions on custom servers

Details

Impact

Workarounds

Workarounds

Severity

References

Release Notes

v15.5.21

v15.5.20

v15.5.19: 15.5.19

Core Changes

Other

Credits

Configuration

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Deploying selfie with Cloudflare Pages

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renovate Bot commented Jul 27, 2026 •

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`v15.5.21`

`v15.5.20`

`v15.5.19`: 15.5.19