# Coraza: Truncated multipart body bypasses MULTIPART_STRICT_ERROR (rule 200003) via silent io.ErrUnexpectedEOF handling

Advisory record · `GHSA-r3rm-qphw-hh76`

- **Identifiers:** `GHSA-r3rm-qphw-hh76` · `CVE-2026-41508` · `GO-2026-6670`
- **State:** Confirmed
- **Severity:** CVSS 5.8 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-20](https://cwe.mitre.org/data/definitions/20.html) · [CWE-693](https://cwe.mitre.org/data/definitions/693.html) · [CWE-755](https://cwe.mitre.org/data/definitions/755.html)
- **Tags:** [CWE-20](https://agentprime.io/advisories/tag/cwe-20.md) · [CWE-693](https://agentprime.io/advisories/tag/cwe-693.md) · [CWE-755](https://agentprime.io/advisories/tag/cwe-755.md)
- **Published:** 6 Oct 2026
- **Updated:** 20 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 6 Oct 2026, 20:37 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `github.com/corazawaf/coraza/v3` (Go): affected `>=3.4.0, <3.8.0`; fixed in `3.8.0`

## Machine-written summary

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

> Coraza (github.com/corazawaf/coraza/v3) versions 3.4.0 up to but not including 3.8.0 fail to set MULTIPART_STRICT_ERROR when a multipart request body is truncated, because io.ErrUnexpectedEOF is silently ignored. A remote attacker can send a truncated multipart body so that the strict-error rule (200003) does not fire, bypassing that defense-in-depth check for other multipart evasions. Upgrade to version 3.8.0 or later.

Written 1 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

- 5.8 Medium, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0050, the 42nd percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:11 UTC: First seen by agentprime
- 31 Oct 2026, 14:11 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-r3rm-qphw-hh76)

## Sources

- [GitHub Advisory Database: GHSA-r3rm-qphw-hh76](https://github.com/advisories/GHSA-r3rm-qphw-hh76)
- [OSV: GHSA-r3rm-qphw-hh76](https://osv.dev/vulnerability/GHSA-r3rm-qphw-hh76)
- <https://github.com/corazawaf/coraza/security/advisories/GHSA-r3rm-qphw-hh76>
- <https://github.com/corazawaf/coraza/commit/f94c81bec209f658120c418448d0590a549b71df>
- <https://github.com/corazawaf/coraza>
- <https://github.com/corazawaf/coraza/releases/tag/v3.8.0>

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-r3rm-qphw-hh76>, 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-r3rm-qphw-hh76/>. Everything for agents: <https://agentprime.io/llms.txt>.