CVE-2021-39935
CVE-2021-39935 is a security flaw in GitLab Community and Enterprise Editions, software teams use to store and build code. Attackers can make GitLab Community and Enterprise Editions send requests into the network behind it. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 3 Feb 2026.[1]
GitLab Community and Enterprise Editions is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. GitLab has published a fix or advice.
Description
CISA calls it a server-side request forgery (SSRF) in GitLab Community and Enterprise Editions. In its words: “GitLab Community and Enterprise Editions contain a server-side request forgery vulnerability which could allow unauthorized external users to perform Server Side Requests via the CI Lint API.”[1]
The CVE record adds: “An issue has been discovered in GitLab CE/EE affecting all versions starting from 10.5 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2. Unauthorized external users could perform Server Side Requests via the CI Lint API”[2]
The underlying weakness is server-side request forgery (CWE-918), in MITRE’s list of common software weaknesses.
It scores 7.5 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; GitLab’s advisory has them[3]. CISA names the product as GitLab Community and Enterprise Editions.
Most families won’t have GitLab Community and Enterprise Editions; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 3 Feb 2026, 1,513 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 24 Feb 2026 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 36%. That’s in the top 2% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
GitLab has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.”[1]
- Check whether you use it.GitLab Community and Enterprise Editions is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed, or not in use. CISA gave US government agencies until 24 Feb 2026 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 7.5.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 36%.[4] |
See also
Other GitLab Community and Enterprise Editions flaws
- CVE-2021-22205: remote code execution ·
Other GitLab flaws
- CVE-2026-97229, GitLab Community Edition and Enterprise Edition: integer overflow or wraparound ·
- CVE-2026-85706, GitLab Community Edition and Enterprise Edition: path traversal ·
- CVE-2021-22175, GitLab: server-side request forgery (SSRF) ·
- CVE-2023-7028, GitLab CE/EE: community and enterprise editions improper access control ·
Other server-side request forgery flaws
- CVE-2026-96655, Plex Media Server: server-side request forgery (SSRF) ·
- CVE-2026-96652, Plex Media Server: server-side request forgery (SSRF) ·
- CVE-2026-83548, SonicWall SMA1000 Appliances: server-side request forgery ·
- CVE-2026-64849, MLflow: server-side request forgery ·
- CVE-2026-15409, SonicWall SMA1000 Appliances: server-side request forgery ·
Added the same day
- CVE-2025-64328, Sangoma FreePBX: OS command injection ·
- CVE-2025-40551, SolarWinds Web Help Desk: deserialization of untrusted data ·
- CVE-2019-19006, Sangoma FreePBX: improper authentication ·
Every GitLab flaw on CISA’s list · Everything added in February 2026
References
- ^ Cybersecurity and Infrastructure Security Agency. “GitLab Community and Enterprise Editions Server-Side Request Forgery (SSRF) Vulnerability”. Known Exploited Vulnerabilities Catalog, added 3 Feb 2026.
- ^ National Institute of Standards and Technology. “CVE-2021-39935 Detail”. National Vulnerability Database, published 13 Dec 2021.
- ^ GitLab. Advisories and fixes: about.gitlab.com, gitlab.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.361, percentile 98.5, 31 Oct 2026.
- CVE Program. “CVE-2021-39935”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.