# Symfony: ReDoS in HeaderUtils::split() Reachable Through the Cache-Control Request Header

Advisory record · `GHSA-r925-mgvr-h9cc`

- **Identifiers:** `GHSA-r925-mgvr-h9cc` · `CVE-2026-108082` · `PKSA-5gdh-tt4n-ckh2` · `PKSA-xmwy-rmx5-m7h4`
- **State:** Confirmed
- **Severity:** CVSS 8.7 High
- **Critical:** No
- **Weakness (CWE):** [CWE-1333](https://cwe.mitre.org/data/definitions/1333.html)
- **Tags:** [Denial of service](https://agentprime.io/advisories/tag/dos.md)
- **Published:** 27 Oct 2026
- **Updated:** 27 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 27 Oct 2026, 19:01 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `symfony/http-foundation` (Packagist): affected `>=6.0.1, <6.4.46 || >=7.0.0, <7.4.19 || >=8.0.0, <8.1.7 || >=4.1.0, <5.4.54`; fixed in `6.4.46`, `7.4.19`, `8.1.7`, `5.4.54`
- `symfony/symfony` (Packagist): affected `>=6.0.1, <6.4.46 || >=7.0.0, <7.4.19 || >=8.0.0, <8.1.7 || >=4.1.0, <5.4.54`; fixed in `6.4.46`, `7.4.19`, `8.1.7`, `5.4.54`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 8.7 High, CVSS 4.0: `CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`, from CNA (Checkmarx)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0048, the 41st percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 13:53 UTC: First seen by agentprime
- 31 Oct 2026, 13:53 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-r925-mgvr-h9cc)

## Sources

- [GitHub Advisory Database: GHSA-r925-mgvr-h9cc](https://github.com/advisories/GHSA-r925-mgvr-h9cc)
- [OSV: GHSA-r925-mgvr-h9cc](https://osv.dev/vulnerability/GHSA-r925-mgvr-h9cc)
- <https://github.com/symfony/symfony/security/advisories/GHSA-r925-mgvr-h9cc>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-108082>
- <https://github.com/symfony/symfony/pull/66048>
- <https://github.com/symfony/symfony/pull/66491>
- <https://github.com/symfony/symfony/commit/343a1772ce6ac03e48b228d2d7168d19750e3f36>
- <https://github.com/symfony/symfony/commit/9ffa802e5d7e9fb8ba95eeefd27e863e83b1baca>
- <https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-foundation/CVE-2026-108082.yaml>
- <https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-108082.yaml>
- <https://github.com/symfony/symfony>
- <https://github.com/symfony/symfony/releases/tag/v5.4.54>
- <https://github.com/symfony/symfony/releases/tag/v6.4.48>
- <https://github.com/symfony/symfony/releases/tag/v7.4.21>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-r925-mgvr-h9cc>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-r925-mgvr-h9cc/>. Everything for agents: <https://agentprime.io/llms.txt>.