CVE-2025-12983Network attack vector

Authenticated service interruption via nested Markdown

Published Nov 15, 2025 · Updated Nov 17, 2025

Resource exhaustion in affected GitLab CE/EE releases allows remote authenticated users to interrupt service through crafted nested Markdown. GitLab identifies excessive memory allocation while processing nested formatting patterns, but the public advisory does not name the parser method or responsible operation. A low-privileged authenticated account and a reachable Markdown submission path are required; successful exploitation degrades availability without reported data disclosure or modification.

CVSS severity3.5
Low
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in affected GitLab CE/EE releases allows remote authenticated users to interrupt service through crafted nested Markdown. GitLab identifies excessive memory allocation while processing nested formatting patterns, but the public advisory does not name the parser method or responsible operation. A low-privileged authenticated account and a reachable Markdown submission path are required; successful exploitation degrades availability without reported data disclosure or modification.

The record

CVE
CVE-2025-12983
Published
Nov 15, 2025
Updated
Nov 17, 2025
Vendor
GitLab
Product
GitLab
Classifications
CWE-789, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 15, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 17, 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=16.9 <18.3.6
  2. Affected versionversion=18.4 <18.4.4
  3. Affected versionversion=18.5 <18.5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=16.9 <18.3.6; version=18.4 <18.4.4; version=18.5 <18.5.2

Published CVSS scores

6.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.5GitLab Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-789Memory Allocation with Excessive Size Value
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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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