Gogs is an open source self-hosted Git service. Prior to 0.14.3, the Jupyter Notebook (ipynb) sanitizer endpoint at POST /-/api/sanitize_ipynb allows arbitrary data: URIs without proper restrictions, potentially leading to Cross-Site Scripting (XSS). The endpoint uses bluemonday.UGCPolicy() with p.AllowURLSchemes("data") which permits all data URI schemes including data:text/html, enabling attackers to inject malicious HTML/JavaScript. Additionally, the endpoint has no authentication middleware, allowing any registered user to exploit this vulnerability. This vulnerability is fixed in 0.14.3.
CVE-2026-52816
This medium-severity CVE scores 5.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 62% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- Lower severity and no public exploit yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 5.4
- EG Score
- 5.4(medium)
- EG Risk
- 29(Track)EG Risk 29/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity54% × 45%Exploitation0% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 38%
- KEV
- Not listed
Published
June 23, 2026
Last Modified
June 25, 2026
Advisory Details (4)
Auto-updated Jun 24, 2026Unauthenticated Jupyter Notebook (ipynb) Sanitizer allows arbitrary data: URIs leading to XSS · Advisory · gogs/gogs · GitHub
https://github.com/gogs/gogs/security/advisories/GHSA-3w28-36p9-w9290.14.3
Patch available: gogs/gogs v0.14.3
https://github.com/gogs/gogs/releases/tag/v0.14.3security: restrict ipynb sanitizer to safe image data URIs
Fix merged in gogs/gogs PR #8326 on 2026-06-06 — awaiting tagged release
https://github.com/gogs/gogs/pull/8326commit dd1bd9837aa1 (gogs/gogs)
Fix landed in gogs/gogs commit dd1bd9837aa1 — awaiting tagged release
https://github.com/gogs/gogs/commit/dd1bd9837aa196b3ed3a8ee21e5727b5d7a986a3Vendor Advisories for CVE-2026-52816(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
Go(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| gogs.io/gogs | — | — | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 9× in last 7d / 43× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-26 15:52 UTCEG score recompute
- 2026-07-26 14:54 UTCEPSS rescore
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-24 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 03:19 UTCEG score recompute
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:25 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-15 02:00 UTCEPSS rescore
- 2026-07-13 22:31 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-13 06:13 UTCEPSS rescore
- 2026-07-12 05:46 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-11 08:27 UTCEPSS rescore
- 2026-07-09 19:10 UTCEPSS rescore
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- 2026-07-09 19:10 UTCEPSS rescore
- 2026-07-08 15:16 UTCEPSS rescore
- 2026-07-08 15:16 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-07 13:46 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 16:27 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-06 02:23 UTCEPSS rescore
- 2026-07-05 02:30 UTCEPSS rescore
- 2026-07-04 06:31 UTCEPSS rescore
- 2026-07-01 15:07 UTCEPSS rescore
- 2026-06-30 23:22 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-29 14:06 UTCEPSS rescore
- 2026-06-28 14:07 UTCEPSS rescore
- 2026-06-28 04:56 UTCEPSS rescore
- 2026-06-28 04:56 UTCEPSS rescore
- 2026-06-27 03:08 UTCEPSS rescore
- 2026-06-25 13:49 UTCEPSS rescore
- 2026-06-24 22:04 UTCEG score recompute▲ 5.40
- 2026-06-24 22:03 UTCNVD updateCVSS v3 → 5.4 · CVSS v4 → 5.4
- 2026-06-23 18:21 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-80
- CVE-2019-13923EG 9.6CRITICAL
- CVE-2020-2503EG 9.0CRITICAL
- CVE-2018-19953NVD 6.1EG 9.0 KEVEPSS p98CRITICAL
- CVE-2018-19943NVD 8.0EG 9.0 KEVEPSS p97CRITICAL
- CVE-2020-13965NVD 6.1EG 9.0 KEVEPSS p99CRITICAL
- CVE-2020-13562NVD 6.1EG 8.6EPSS p100HIGH
- CVE-2020-13564NVD 6.1EG 8.5EPSS p99HIGH
- CVE-2020-13563NVD 6.1EG 8.5EPSS p99HIGH
- CVE-2020-26218EG 8.0HIGH
- CVE-2020-5241EG 7.7HIGH
Frequently asked(5)
What is CVE-2026-52816?
When was CVE-2026-52816 disclosed?
Is CVE-2026-52816 actively exploited?
What is the CVSS score of CVE-2026-52816?
How do I remediate CVE-2026-52816?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-52816
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