OAuth token introspection returns metadata of tokens issued to other clients (RFC 7662 section 4 violation)

published 2026-07-21 3 mo ago modified 2026-08-26 2 mo ago also GHSA-vxv2-8j6r-pcpg , GO-2026-6079 , EUVD-2026-58154

cvss: 4.3; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 26%
public exploits: 0; none known

Patch / fix

fixed in 2 distros 2 links 3

go code.gitea.io/gitea 1.27.0
go gitea.dev 1.27.0

suse opensuse

govulncheck-vulndb SLES 16.0, SLES for SAP applications 16.0 0.0.20260727T201416-160000.1.1

suse advisories SUSE-SU-2026:23216-1 SUSE-SU-2026:23227-1

govulncheck-vulndb openSUSE Leap 16.0 0.0.20260727T201416-160000.1.1

opensuse advisories openSUSE-SU-2026:21551-1

github.com/go-gitea/gitea@c9920b7 commit
github.com/go-gitea/gitea#38042 pull request
github.com/go-gitea/gitea/releases/tag/v1.27.0 release

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 2 mo ago (2026-08-14)

Exploit prediction

0.33% chance of exploitation in the next 30 days, higher than 26% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/go-gitea/gitea/security/advisories/GHSA-vxv2-8j6r-pcpg referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CNA	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
GitHub	3.1	4.3	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
go	code.gitea.io/gitea	<1.27.0	1.27.0
go	gitea.dev	<1.27.0	1.27.0

Affected products

Gitea Gitea Open Source Git Server

Classification

Weakness

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
CWE-863 Incorrect Authorization

References

github.com /go-gitea/gitea/pull/38042
web
github.com /go-gitea/gitea/commit/c9920b7bd0f6ec1f7590f104711b09d55917f9e8
web
github.com /go-gitea/gitea/security/advisories/GHSA-vxv2-8j6r-pcpg
vendor-advisory, exploit, web, advisory
github.com /go-gitea/gitea/releases/tag/v1.27.0
release-notes, web
blog.gitea.com /gitea-1.27.0-is-released/
release-notes
github.com /go-gitea/gitea
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary