CVE-2021-22183Public exploitNetwork attack vector

Stored XSS via unsafe milestone title rendering

Published Mar 4, 2021 · Updated Aug 3, 2024

Stored XSS in affected GitLab releases starting with 11.8 allows remote authenticated users to execute script in an epic viewer's browser. The inherited due-date tooltip renders a milestone title containing an SVG use reference without neutralizing script-capable SVG content. The attacker needs project access and victim interaction; browser and CSP behavior govern reachability, while execution exposes data and victim-authorized actions.

CVSS severity4.1
Medium
EPSS probability0.84%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in affected GitLab releases starting with 11.8 allows remote authenticated users to execute script in an epic viewer's browser. The inherited due-date tooltip renders a milestone title containing an SVG use reference without neutralizing script-capable SVG content. The attacker needs project access and victim interaction; browser and CSP behavior govern reachability, while execution exposes data and victim-authorized actions.

The record

CVE
CVE-2021-22183
Published
Mar 4, 2021
Updated
Aug 3, 2024
Vendor
GitLab
Product
GitLab
Classifications
CWE-79, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>=11.8, <13.6.6
  2. Affected versionversion=>=13.7, <13.7.6
  3. Affected versionversion=>=13.8, <13.8.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=>=11.8, <13.6.6; version=>=13.7, <13.7.6; version=>=13.8, <13.8.2

Published CVSS scores

4.1GitLab Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:N/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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