# RCE in Symfony

Advisory record · `GHSA-754h-5r27-7x3r`

- **Identifiers:** `GHSA-754h-5r27-7x3r` · `BIT-symfony-2020-15094` · `CVE-2020-15094` · `PKSA-6pwr-137g-8814` · `PKSA-8knv-7jsn-12w8`
- **State:** Confirmed
- **Severity:** CVSS 8.0 High
- **Critical:** No
- **Weakness (CWE):** [CWE-212](https://cwe.mitre.org/data/definitions/212.html)
- **Tags:** [CWE-212](https://agentprime.io/advisories/tag/cwe-212.md)
- **Published:** 2 Sept 2020
- **Updated:** 8 Jul 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 2 Sept 2020, 17:29 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `symfony/http-kernel` (Packagist): affected `>=4.3.0, <4.4.13 || >=5.0.0, <5.1.5`; fixed in `4.4.13`, `5.1.5`
- `symfony/symfony` (Packagist): affected `>=4.3.0, <4.4.13 || >=5.0.0, <5.1.5`; fixed in `4.4.13`, `5.1.5`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> Symfony's http-kernel and symfony packages, versions 4.3.0 up to 4.4.13 and 5.0.0 up to 5.1.5, are affected. When CachingHttpClient is used, an attacker who controls the response to a request it makes can exploit internal cache headers in HttpCache to achieve remote code execution. Upgrade to symfony/http-kernel or symfony/symfony 4.4.13 or 5.1.5, or later.

Written 3 Nov 2026.

## 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

- 8.0 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.030, the 87th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:25 UTC: First seen by agentprime
- 31 Oct 2026, 14:25 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-754h-5r27-7x3r)

## Sources

- [GitHub Advisory Database: GHSA-754h-5r27-7x3r](https://github.com/advisories/GHSA-754h-5r27-7x3r)
- [OSV: GHSA-754h-5r27-7x3r](https://osv.dev/vulnerability/GHSA-754h-5r27-7x3r)
- <https://github.com/symfony/symfony/security/advisories/GHSA-754h-5r27-7x3r>
- <https://nvd.nist.gov/vuln/detail/CVE-2020-15094>
- <https://github.com/symfony/symfony/commit/d9910e0b33a2e0f993abff41c6fbc86951b66d78>
- <https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/http-kernel/CVE-2020-15094.yaml>
- <https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2020-15094.yaml>
- <https://github.com/symfony/symfony>
- <https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/HNGUWOEETOFVH4PN3I3YO4QZHQ4AUKF3>
- <https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/VAQJXAKWPMWB7OL6QPG2ZSEQZYYPU5RC>
- <https://packagist.org/packages/symfony/http-kernel>
- <https://packagist.org/packages/symfony/symfony>
- <https://symfony.com/cve-2020-15094>

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-754h-5r27-7x3r>, 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-754h-5r27-7x3r/>. Everything for agents: <https://agentprime.io/llms.txt>.