Gogs: LFS dedupe path leaks private repo content across tenants

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

7.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:L/SI:N/SA:N · score source

EPSS

• CVE-2026-52812: 0.24% estimated exploitation activity in the next 30 days; percentile 14.73 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Git LFS storage is content-addressed by OID alone (<LFS-root/<oid[0]/<oid[1]/<oid) but per-repo authorization lives in the lfsobject table keyed (repoid, oid). serveUpload skips re-uploading when the OID file already exists on disk and inserts a new (repoid, oid) row pointing at it without verifying the request body hashes to the OID being claimed. Any user with write access to one repo can bind their repo to an OID owned by a private repo and download the original bytes via their own download endpoint. Details Dedupe shortcut at internal/lfsx/storage.go:79-82: Hash verification at internal/lfsx/storage.go:106-108 only runs in the new-file branch — the dedupe path returns earlier. serveUpload (internal/route/lfs/basic.go:78-114) trusts that success and inserts the per-repo binding: CreateLFSObject is an unconditional INSERT on (repoid, oid) with no check that the OID is referenced by the requesting repo's git history. serveDownload at internal/route/lfs/basic.go:42-72 only…

Published by the source

23 Jun 2026, 17:10 UTC

Last modified by the source

21 Jul 2026, 13:40 UTC

Source last checked

26 Oct 2026, 15:27 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6p9m-q3jp-47h4

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# Patch Next advisory brief: CVE-2026-52812

Advisory: Gogs: LFS dedupe path leaks private repo content across tenants
IDs: CVE-2026-52812, GHSA-6p9m-q3jp-47h4
Record: https://patchnext.com/advisories/cve-2026-52812 (revision 1, source checked 26 Oct 2026, 15:27 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: gogs.io/gogs 0.14.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go gogs.io/gogs: affected < 0.14.3; fixed in 0.14.3

## Suggested inspection (read-only)
- Go gogs.io/gogs: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on gogs.io/gogs.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-6p9m-q3jp-47h4 (GitHub-reviewed advisory GHSA-6p9m-q3jp-47h4 lists affected ranges: Go gogs.io/gogs >=0 <0.14.3)

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