# Apache Tomcat's DIGEST authenticator has an Authentication Bypass by Capture-replay vulnerability

Advisory record · `GHSA-9xv2-5v5q-p794`

- **Identifiers:** `GHSA-9xv2-5v5q-p794` · `BIT-tomcat-2026-65905` · `CVE-2026-65905`
- **State:** Confirmed
- **Severity:** CVSS 9.8 Critical
- **Critical:** Yes: CVSS 9+
- **Weakness (CWE):** [CWE-294](https://cwe.mitre.org/data/definitions/294.html)
- **Tags:** [Authentication bypass](https://agentprime.io/advisories/tag/auth-bypass.md)
- **Published:** 26 Aug 2026
- **Updated:** 11 Sept 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 26 Aug 2026, 00:30 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Critical

Critical, because:

- CVSS score 9.8: 9.0 or more.

How we decide what’s critical: <https://agentprime.io/advisories/critical.md>

## Affected packages

- `org.apache.tomcat:tomcat` (Maven): affected `>=11.0.0-M1, <11.0.25 || >=10.1.0-M1, <10.1.58 || >=9.0.0.M1, <9.0.121 || >=8.5.0, <=8.5.100 || >=7.0.30, <=7.0.109`; fixed in `11.0.25`, `10.1.58`, `9.0.121`
- `org.apache.tomcat.embed:tomcat-embed-core` (Maven): affected `>=11.0.0-M1, <11.0.25 || >=10.1.0-M1, <10.1.58 || >=9.0.0.M1, <9.0.121 || >=8.5.0, <=8.5.100 || >=7.0.30, <=7.0.109`; fixed in `11.0.25`, `10.1.58`, `9.0.121`
- `org.apache.tomcat:tomcat-catalina` (Maven): affected `>=11.0.0-M1, <11.0.25 || >=10.1.0-M1, <10.1.58 || >=9.0.0.M1, <9.0.121 || >=8.5.0, <=8.5.100 || >=7.0.30, <=7.0.109`; fixed in `11.0.25`, `10.1.58`, `9.0.121`

## Machine-written summary

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

> Apache Tomcat (org.apache.tomcat:tomcat, tomcat-embed-core and tomcat-catalina) versions 11.0.0-M1 through 11.0.24, 10.1.0-M1 through 10.1.57, 9.0.0.M1 through 9.0.120, and older unsupported versions are affected. A client using DIGEST authentication can, under specific nonce count conditions, replay one captured request and bypass authentication. Upgrade to 11.0.25, 10.1.58, or 9.0.121.

Written 2 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

- 9.8 Critical, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** 0.0076, the 55th percentile, on 7 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:16 UTC: First seen by agentprime
- 31 Oct 2026, 14:16 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-9xv2-5v5q-p794)

## Sources

- [GitHub Advisory Database: GHSA-9xv2-5v5q-p794](https://github.com/advisories/GHSA-9xv2-5v5q-p794)
- [OSV: GHSA-9xv2-5v5q-p794](https://osv.dev/vulnerability/GHSA-9xv2-5v5q-p794)
- <https://nvd.nist.gov/vuln/detail/CVE-2026-65905>
- <https://github.com/apache/tomcat>
- <https://lists.apache.org/thread/9v114xlpgbzrrbzz5vf9f6r2q4wnxwwj>
- <http://www.openwall.com/lists/oss-security/2026/08/26/4>

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-9xv2-5v5q-p794>, 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-9xv2-5v5q-p794/>. Everything for agents: <https://agentprime.io/llms.txt>.
