CVE-2022-4131Public exploitNetwork attack vector

Authenticated service interruption via user-agent regex backtracking

Published Jan 12, 2023 · Updated Apr 8, 2025

ReDoS in affected GitLab CE/EE releases allows remote authenticated users to interrupt service via a crafted User-Agent header. The device-detector gem applies the Chrome/(\d+[.\d]+).*MRCHROME expression to the header, whose overlapping digit matches trigger cubic backtracking when the terminal marker is absent. A valid login and session cookies are required; each malicious request consumes a CPU core until the 60-second timeout and returns an HTTP 500 response.

CVSS severity4.3
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

ReDoS in affected GitLab CE/EE releases allows remote authenticated users to interrupt service via a crafted User-Agent header. The device-detector gem applies the Chrome/(\d+[.\d]+).*MRCHROME expression to the header, whose overlapping digit matches trigger cubic backtracking when the terminal marker is absent. A valid login and session cookies are required; each malicious request consumes a CPU core until the 60-second timeout and returns an HTTP 500 response.

The record

CVE
CVE-2022-4131
Published
Jan 12, 2023
Updated
Apr 8, 2025
Vendor
GitLab
Product
GitLab
Classifications
CWE-1333, T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 12, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 8, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=>=10.8, <15.5.7
  2. Affected versionversion=>=15.6, <15.6.4
  3. Affected versionversion=>=15.7, <15.7.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=>=10.8, <15.5.7; version=>=15.6, <15.6.4; version=>=15.7, <15.7.2

Published CVSS scores

4.3GitLab Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
5.3NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1333Inefficient Regular Expression Complexity
T1499.004Application or System Exploitation

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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