CVE-2025-12734Network attack vectorHinoki check available

Dialog content injection via unencoded merge request titles

Published Dec 11, 2025 · Updated Dec 11, 2025

HTML injection in affected GitLab CE/EE releases allows remote authenticated users to render content in other users' dialogs via crafted titles. The dialog rendering path treats attacker-controlled merge request titles as HTML instead of encoding them as safe text output. Exploitation requires another user's interaction; affected ranges are 15.6 before 18.4.6, 18.5 before 18.5.4, and 18.6 before 18.6.2, with integrity impact limited to rendered dialog content.

CVSS severity3.5
Low
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

HTML injection in affected GitLab CE/EE releases allows remote authenticated users to render content in other users' dialogs via crafted titles. The dialog rendering path treats attacker-controlled merge request titles as HTML instead of encoding them as safe text output. Exploitation requires another user's interaction; affected ranges are 15.6 before 18.4.6, 18.5 before 18.5.4, and 18.6 before 18.6.2, with integrity impact limited to rendered dialog content.

The record

CVE
CVE-2025-12734
Published
Dec 11, 2025
Updated
Dec 11, 2025
Vendor
GitLab
Product
GitLab
Classifications
CWE-116
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 11, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 11, 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=15.6 <18.4.6
  2. Affected versionversion=18.5 <18.5.4
  3. Affected versionversion=18.6 <18.6.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=15.6 <18.4.6; version=18.5 <18.5.4; version=18.6 <18.6.2

Published CVSS scores

3.5GitLab Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-116Improper Encoding or Escaping of Output

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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