CVE-2023-3904Public exploitNetwork attack vector

Authenticated issue-board denial of service via time overflow

Published Dec 15, 2023 · Updated Aug 14, 2026

Validation flaw in GitLab EE 16.4.3 and earlier, 16.5 through 16.5.3, and 16.6 through 16.6.1 allows remote authenticated users to block issue boards. The createTimelog GraphQL mutation accepts an unvalidated timeSpent value, and repeated extreme entries overflow the total used by board and time-tracking views. A user able to add time to an issue can make its time-tracking report and board entry unavailable to other users.

CVSS severity4.3
Medium
EPSS probability0.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Validation flaw in GitLab EE 16.4.3 and earlier, 16.5 through 16.5.3, and 16.6 through 16.6.1 allows remote authenticated users to block issue boards. The createTimelog GraphQL mutation accepts an unvalidated timeSpent value, and repeated extreme entries overflow the total used by board and time-tracking views. A user able to add time to an issue can make its time-tracking report and board entry unavailable to other users.

The record

CVE
CVE-2023-3904
Published
Dec 15, 2023
Updated
Aug 14, 2026
Vendor
GitLab
Product
GitLab
Classifications
CWE-1287, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 14, 2026Record 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=0 <=16.4.3
  2. Affected versionversion=16.5 <16.5.4
  3. Affected versionversion=16.6 <16.6.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

GitLab · GitLabversion=0 <=16.4.3; version=16.5 <16.5.4; version=16.6 <16.6.2

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
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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-1287Improper Validation of Specified Type of Input
T1499Endpoint Denial of Service

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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