CVE-2025-2255Public exploitNetwork attack vector

Victim-session actions via rendered merge errors

Published Mar 27, 2025 · Updated Mar 27, 2025

Cross-site scripting in affected GitLab releases allows remote authenticated users to execute actions in another user's browser. The merge-request widget treats attacker-controlled merge_error content as safe HTML, allowing crafted elements to bypass the content security policy. Exploitation requires importing a modified project export and persuading a project member to interact with the merge-request overview, after which the script acts with that member's session.

CVSS severity8.7
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in affected GitLab releases allows remote authenticated users to execute actions in another user's browser. The merge-request widget treats attacker-controlled merge_error content as safe HTML, allowing crafted elements to bypass the content security policy. Exploitation requires importing a modified project export and persuading a project member to interact with the merge-request overview, after which the script acts with that member's session.

The record

CVE
CVE-2025-2255
Published
Mar 27, 2025
Updated
Mar 27, 2025
Vendor
GitLab
Product
GitLab
Classifications
CWE-79
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 27, 2025CVE publishedPublication date reported by the CVE source.
  2. Mar 27, 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=13.5.0 <17.8.6
  2. Affected versionversion=17.10 <17.10.1
  3. Affected versionversion=17.9 <17.9.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=13.5.0 <17.8.6; version=17.10 <17.10.1; version=17.9 <17.9.3

Published CVSS scores

8.7GitLab Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/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 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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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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