Is CVE-2026-52816 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-52816 being exploited in the wild.

How severe is CVE-2026-52816?

Medium severity, with a CVSS score of 4, published 24 June 2026.

Which products and versions are affected?

gogs.io/gogs (Go) < 0.14.3, SEMVER:introduced=0, SEMVER:introduced=0,fixed=0.14.3; Gogs < 0.14.3.

Is there a fix for CVE-2026-52816?

Yes. gogs.io/gogs (Go): upgrade to 0.14.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-52816 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-52816?

Check whether you run gogs.io/gogs (Go) or Gogs at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-52816: Gogs stored XSS in Jupyter Notebook sanitizer endpoint

Q: Which products and versions are affected?

gogs.io/gogs (Go) < 0.14.3, SEMVER:introduced=0, SEMVER:introduced=0,fixed=0.14.3; Gogs < 0.14.3.

Q: Is there a fix for CVE-2026-52816?

Yes. gogs.io/gogs (Go): upgrade to 0.14.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2026-52816 attacked?

It is attacked over the network, in a network appliance.

Q: Am I affected by CVE-2026-52816?

Check whether you run gogs.io/gogs (Go) or Gogs at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-52816 · Severity: medium · CVSS 4 · Published 2026-06-24

Gogs is an open-source self-hosted Git service used by developers to manage source code. A security flaw in how the platform handles Jupyter Notebook files allows attackers to bypass security filters and inject malicious scripts. If a user is tricked into interacting with a specially crafted notebook preview, an attacker could execute unauthorized actions or steal sensitive information from the user's session.

Technologies: gogs.io/gogs (Go), Gogs. Vendors: Go, Gogs.

Quick answers

Is CVE-2026-52816 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-52816 being exploited in the wild.
How severe is CVE-2026-52816?: Medium severity, with a CVSS score of 4, published 24 June 2026.
Which products and versions are affected?: gogs.io/gogs (Go) < 0.14.3, SEMVER:introduced=0, SEMVER:introduced=0,fixed=0.14.3; Gogs < 0.14.3.
Is there a fix for CVE-2026-52816?: Yes. gogs.io/gogs (Go): upgrade to 0.14.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-52816 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-52816?: Check whether you run gogs.io/gogs (Go) or Gogs at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

gogs.io/gogs (Go): upgrade to 0.14.3 or later
```
go get gogs.io/gogs@v0.14.3
```

Technical details

A Cross-Site Scripting (XSS) vulnerability exists in Gogs' Jupyter Notebook (.ipynb) sanitization endpoint. The 'POST /-/api/sanitize_ipynb' endpoint utilizes the bluemonday library with a policy that explicitly allows all 'data:' URI schemes via 'p.AllowURLSchemes("data")'. This configuration fails to restrict the MIME types allowed within the data URI, permitting 'data:text/html' payloads containing malicious JavaScript. Furthermore, the endpoint lacks authentication middleware, making it accessible to any registered user. An attacker can submit crafted HTML to the endpoint and receive a response where the malicious script is preserved, which executes when rendered in a victim's browser context. This was resolved in version 0.14.3 by implementing a restricted allowlist for safe image MIME types.

Affected products

Gogs Gogs < 0.14.3

Identifiers

CVE-2026-52816
GHSA-3w28-36p9-w929
GO-2026-5103

Timeline

2026-06-06: patched: Fix merged into main branch
2026-06-07: advisory: Version 0.14.3 released
2026-06-24: disclosed: CVE-2026-52816 published

References

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