# CVE-2026-52807: Gogs: DOM-based XSS via Milestone Name on New Issue Page

> An attacker can execute arbitrary JavaScript in a victim's browser by storing a malicious payload in a milestone name within the Gogs Git service.

- **Severity:** Medium 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`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 24 Jun 2026
- **Updated:** 25 Jun 2026
- **Also known as:** GHSA-vcm5-gvmp-78mp, GO-2026-5661

## What is CVE-2026-52807?

CVE-2026-52807 is a medium-severity cross-site scripting vulnerability in gogs, published on 24 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

Gogs is an open source self-hosted Git service. Prior to 0.14.3, in new_form.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. Semantic UI 2.4.2's dropdown component has preserveHTML: true as the default setting. When a user selects a dropdown item, the internal set.text() method calls jQuery's .html() with the item's text content. This re-parses the decoded text as HTML, creating the injected element and triggering the JavaScript event handler. 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. This vulnerability is fixed in 0.14.3.

Weakness: CWE-79 (Improper Neutralization of Input During Web Page Generation)

## Which versions are affected by CVE-2026-52807?

3 open source packages ship an affected version, including gogs.io/gogs.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `gogs.io/gogs` | Go | All versions | None |
| `gogs.io/gogs` | Go | All versions | 0.14.3 |
| `gogs.io/gogs` | Go | All versions | 0.14.3 |

## How do I fix CVE-2026-52807?

Upgrade gogs.io/gogs to 0.14.3 or later.

## Is CVE-2026-52807 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-52807 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-52807 and fix it if it is affected.

What it is: CVE-2026-52807 is a medium-severity cross-site scripting vulnerability in gogs, published on 24 Jun 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-52807 exists.

Affected packages and fixed versions:
- gogs.io/gogs (Go): affected all versions; no fix listed
- gogs.io/gogs (Go): affected all versions; fixed in 0.14.3
- gogs.io/gogs (Go): affected all versions; fixed in 0.14.3

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-52807/ (Markdown: https://insights.sbomify.com/CVE-2026-52807/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-52807
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-52807
- OSV: https://osv.dev/vulnerability/CVE-2026-52807

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-52807/
Summaries are generated and may contain mistakes; the official description above is the record.