CVE-2026-100755: Acceptance of Extraneous Untrusted Data With Trusted Data in GitLab

Q: Which GitLab versions require remediation?

Affected versions are all releases from 16.2 before 19.2.8, 19.3 before 19.3.5, and 19.4 before 19.4.2. Upgrade to 19.2.8, 19.3.5, 19.4.2, or a later release in the applicable release line.

Q: Who can exploit this issue?

Exploitation requires an authenticated GitLab user. The issue is only described as affecting certain deployment configurations, and it requires a high-complexity attack plus user interaction.

Q: What is the likely impact if exploitation succeeds?

An attacker could poison cached page content that is subsequently served to other users. The reported impact includes limited confidentiality, integrity, and availability effects.

Published Oct 13, 2026

Updated

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 16.2 before 19.2.8, 19.3 before 19.3.5, and 19.4 before 19.4.2 that, under certain deployment configurations, could have allowed an authenticated user to poison cached page content served to other users due to improper cache key construction.

Affected Software

1 affected component

GitLab GitLab CE/EE>=16.2<19.2.8, >=19.3<19.3.5, >=19.4<19.4.2

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade GitLab CE/EE to a version that resolves this vulnerability.
Fixed in 19.2.8
Upgrade
Upgrade GitLab CE/EE to a version that resolves this vulnerability.
Fixed in 19.3.5
Upgrade
Upgrade GitLab CE/EE to a version that resolves this vulnerability.
Fixed in 19.4.2

Event History

Oct 13, 2026

CVE Published

via MITRE·01:05 AM

Data Sourced

via MITRE·01:05 AM

RemedyDescriptionSeverityWeakness

Data Sourced

via NVD·02:16 AM

DescriptionSeverityWeakness

Frequently Asked Questions

Which GitLab versions require remediation?

Affected versions are all releases from 16.2 before 19.2.8, 19.3 before 19.3.5, and 19.4 before 19.4.2. Upgrade to 19.2.8, 19.3.5, 19.4.2, or a later release in the applicable release line.

Who can exploit this issue?

Exploitation requires an authenticated GitLab user. The issue is only described as affecting certain deployment configurations, and it requires a high-complexity attack plus user interaction.

What is the likely impact if exploitation succeeds?

An attacker could poison cached page content that is subsequently served to other users. The reported impact includes limited confidentiality, integrity, and availability effects.

CVE-2026-100755: Acceptance of Extraneous Untrusted Data With Trusted Data in GitLab

Affected Software

Remediation

Event History

Frequently Asked Questions

Which GitLab versions require remediation?

Who can exploit this issue?

What is the likely impact if exploitation succeeds?

Company

Resources

Contact

Frequently Asked Questions

Which GitLab versions require remediation?

Who can exploit this issue?

What is the likely impact if exploitation succeeds?