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GitLabApplication

CVE-2021-39946

MEDIUM · 5.4 CVSS v3.1 Published 2022-01-18
Fix available
A fix is available. Upgrade to 14.3.6 / 14.4.4 or later.
See remediation →
58/100
Remediation priority · Elevated
Remotely reachable

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Improper neutralization of user input in GitLab CE/EE versions 14.3 to 14.3.6, 14.4 to 14.4.4, and 14.5 to 14.5.2 allowed an attacker to exploit XSS by abusing the generation of the HTML code related to emojis

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Improper neutralization of user input in GitLab's emoji HTML code generation allowed an attacker to inject malicious scripts via XSS. The vulnerability affects GitLab CE/EE versions 14.3 through 14.3.6, 14.4 through 14.4.4, and 14.5 through 14.5.2.

MitigationUpgrade GitLab to a patched version beyond 14.5.2 to resolve the improper input sanitization in emoji HTML rendering.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
GitLabApplication
Affected:>= 14.3, < 14.3.6>= 14.4, < 14.4.4>= 14.5, < 14.5.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed GitLab version
    Run `gitlab-rake gitlab:env:info` or check the GitLab admin dashboard under Help > Version to see the exact installed version.
    Affected if The version falls within 14.3.0-14.3.6, 14.4.0-14.4.4, or 14.5.0-14.5.2.
  2. Confirm GitLab web interface is accessible
    Verify that the GitLab web application is running and users can access it via browser.
    Affected if The web interface is active and users can interact with emoji functionality.
  3. Identify if emoji reactions feature is enabled
    Check if users can react to issues, merge requests, or comments with emojis. This is a default feature in GitLab but can be verified in Admin Area > Settings > General under 'Visibility and access controls'.
    Affected if Emoji reactions are allowed on the instance (default behavior).

You are affected if your GitLab version is 14.3.x between 14.3.0-14.3.6, 14.4.x between 14.4.0-14.4.4, or 14.5.x between 14.5.0-14.5.2 and users can add emoji reactions via the web interface.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 14.3.6 / 14.4.4 / 14.5.2 or later
Fixed in 14.3.614.4.414.5.2
Interim mitigation

Upgrade GitLab to a patched version beyond 14.5.2 to resolve the improper input sanitization in emoji HTML rendering.

Recommended fix High confidence

Upgrade to GitLab 14.3.6, 14.4.4, or 14.5.2 (or later stable release)

  1. Identify current GitLab version by checking the GitLab admin area or running `gitlab-rake gitlab:env:info`
  2. Backup the GitLab instance before proceeding with the upgrade
  3. Plan upgrade path based on current version: if on 14.3.x upgrade to 14.3.6 or later; if on 14.4.x upgrade to 14.4.4 or later; if on 14.5.x upgrade to 14.5.2 or later
  4. For Omnibus installations: run `sudo gitlab-ctl stop` then `sudo apt-get update && sudo apt-get install gitlab-ce` (or gitlab-ee)
  5. For source installations: follow the upgrade guide at https://docs.gitlab.com/ee/update/
  6. After upgrade, run `sudo gitlab-ctl restart` and verify the instance is operational
  7. Confirm the version has been updated by checking the admin dashboard or running `gitlab-rake gitlab:env:info`
Caveat Review GitLab upgrade notes for any configuration changes or database migrations required between your current and target version

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in GitLab Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-39946 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data