CVE-2026-87719

Deserialization of Untrusted Data in GitLab

CRITICAL

9.9

CVSS Score

Published: September 12, 2026 at 02:46 AM UTC

Updated: September 28, 2026 at 07:08 PM UTC

1 product affected across 1 vendorGitLab

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Severity

CRITICAL9.9

Exploit prediction

EPSS 0.6%

SSVC

No known exploit

Description

GitLab has remediated an issue in GitLab EE affecting all versions from 18.3 before 19.1.8, 19.2 before 19.2.6, and 19.3 before 19.3.2 that under certain conditions could allow an authenticated user with Duo Chat access to obtain Advanced Search instance configurations and sensitive credentials using a specially crafted GraphQL subscription argument to bypass serialization and perform server object lookup.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

GitLab · GitLabmaven

95%

18.3 ≤ v < 18.11.1218.3.0 ≤ v < 18.11.1219.0 ≤ v < 19.0.919.0.0 ≤ v < 19.0.919.1 ≤ v < 19.1.819.1.0 ≤ v < 19.1.819.2 ≤ v < 19.2.619.2.0 ≤ v < 19.2.619.3 ≤ v < 19.3.219.3.0 ≤ v < 19.3.218.3 19.0 19.1 19.2 19.3

Affected range stops below 18.11.12, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.0.9, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.1.8, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.2.6, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.3.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (2)

Broken Link

Source: cverecord

https://gitlab.com/gitlab-org/gitlab/-/work_items/628160

Technical DescriptionExploitPermissions Required

Source: cverecord

https://hackerone.com/reports/4012289

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

9.9CRITICALGitLab

Attack Vector: NETWORK
Complexity: LOW
Privileges: LOW
User Interaction: NONE
Scope: CHANGED
Confidentiality: HIGH
Integrity: HIGH
Availability: HIGH

Vector?

Quick Info

StatusANALYZED

CWE

CWE-502

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