Medium severity · published Aug 28, 2026
CVE-2026-55867
Graylog token revocation endpoint allows authenticated users to delete other users’ access tokens
5.3
CVSS
0.6%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 47% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GR
graylog2-server · Graylog2
>= 6.2.0, < 6.3.12; >= 7.0.0-alpha.1, < 7.0.7; >= 7.1.0-alpha.1, < 7.1.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-55867
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-55867
github.com
https://github.com/Graylog2/graylog2-server/commit/41d3745d0e52736d06c07d279ca0d72c1616df4c
github.com
https://github.com/Graylog2/graylog2-server/commit/4f280138b53dc3bbb5749213e8cb1c8e372f23a2
github.com
https://github.com/Graylog2/graylog2-server/commit/84b0ffa0bdf918f6edd2bb23a47254088634b1fc
github.com
https://github.com/Graylog2/graylog2-server/commit/e5accc5f4ce48bd61b84bb8e5a13d21f8eac3da5
github.com
https://github.com/Graylog2/graylog2-server/pull/26049
github.com
https://github.com/Graylog2/graylog2-server/pull/26051
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