Gitea private attachment disclosure through repository mismatch

Published 24 d ago 2026-10-14 · modified 20 d ago 2026-10-18 · JSON

CVSS

5.9

v3.1 · CNA

CISA KEV

not known exploited

EPSS

0.4%

percentile 31%

Public exploits

none known

Gitea's web attachment handler skips its cross-repository ownership check for attachments created before 16 January 2026 and checks permissions against the repository named in the request URL instead. An unauthenticated attacker who knows a private attachment's UUID can request it through a public repository's attachment path and retrieve its contents. This can expose issue and pull request attachments or release assets; the random attachment UUID must already be known to the attacker.

CISA SSVC assessment

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 20 d ago 2026-10-18

Exploit prediction (EPSS)

0.37% probability of exploitation in the next 30 days, higher than 31% of all scored CVEs.

CVSS scores

Assigned by	Version	Score	Vector
CISA ADP	3.1	5.9	`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`
CNA	3.1	5.9	`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N`

Affected products

Gitea Gitea

Classification

Weakness

CWE-284 Improper Access Control
CWE-639 Authorization Bypass Through User-Controlled Key
CWE-863 Incorrect Authorization
CWE-1220 Insufficient Granularity of Access Control

References

github.com /go-gitea/gitea/security/advisories/GHSA-frpv-2xgv-wxpq · vendor-advisory
blog.gitea.com /release-of-1.27.3/ · release-notes
github.com /go-gitea/gitea/pull/39048 · patch
github.com /go-gitea/gitea/pull/39077 · patch
github.com /go-gitea/gitea/releases/tag/v1.27.3 · release-notes

Sources

CVE List: CVE-2026-78433
NVD: CVE-2026-78433

vulnwire keeps one entry per vulnerability: the CVE id wins, then GHSA; records that alias each other are merged. Machine-readable: JSON.

Summary