Gogs has DOM-based XSS via Milestone Name on New Issue Page

Exploitation

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

CVSS 4.0

4.8 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X · score source

EPSS

• CVE-2026-52807: 0.48% estimated exploitation activity in the next 30 days; percentile 41.70 (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 The fix for GHSA-vgjm-2cpf-4g7c (DOM-based XSS via milestone selection) was only applied to templates/repo/issue/viewcontent.tmpl but not to templates/repo/issue/newform.tmpl. An attacker can store an HTML/JavaScript payload in a milestone name, and when any user opens the New Issue page and interacts with the milestone dropdown, the payload executes in their browser via Semantic UI's preserveHTML behavior. Details GHSA-vgjm-2cpf-4g7c was patched by adding | Sanitize (bluemonday HTML tag stripping) to milestone name rendering in viewcontent.tmpl. However, the same milestone dropdown exists in newform.tmpl and was not patched. In newform.tmpl, milestone names are rendered with Go's default auto-escaping ({{.Name}}), which converts < to &lt; etc. This prevents direct HTML injection. However, when the browser renders the DOM, the text content of the element contains the decoded original payload (e.g., <img src=x onerror=alert(1)). Semantic UI 2.4.2's dropdown component has…

Published by the source

23 Jun 2026, 17:02 UTC

Last modified by the source

21 Jul 2026, 13:35 UTC

Source last checked

26 Oct 2026, 15:27 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vcm5-gvmp-78mp

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# Patch Next advisory brief: CVE-2026-52807

Advisory: Gogs has DOM-based XSS via Milestone Name on New Issue Page
IDs: CVE-2026-52807, GHSA-vcm5-gvmp-78mp
Record: https://patchnext.com/advisories/cve-2026-52807 (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: Medium (CVSS 4.8)
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-vcm5-gvmp-78mp (GitHub-reviewed advisory GHSA-vcm5-gvmp-78mp lists affected ranges: Go gogs.io/gogs >=0 <0.14.3)

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