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Mallory
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Denial of Service in GitLab GraphQL API

IdentifiersCVE-2025-12664CWE-1284· Improper Validation of Specified…

CVE-2025-12664 is a denial-of-service vulnerability in the GitLab CE/EE GraphQL API affecting self-managed installations. It impacts all versions from 13.0 before 18.8.9, 18.9 before 18.9.5, and 18.10 before 18.10.3. The issue stems from improper validation of the quantity of unauthenticated GraphQL requests to the /api/graphql endpoint, classified as CWE-1284. An attacker can repeatedly send GraphQL queries over HTTP without authentication and overwhelm backend resources. Available reporting indicates the flaw is volumetric in nature rather than a single-query complexity issue; existing GraphQL complexity scoring and per-request timeout controls did not prevent exploitation. Successful abuse can consume CPU, memory, and Sidekiq worker capacity, degrading or interrupting service.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows an unauthenticated remote attacker to cause a high-impact availability failure on vulnerable self-managed GitLab instances. Repeated GraphQL requests can exhaust CPU, memory, and Sidekiq worker resources, create severe latency for legitimate users, cause requests to fail after timeout, fill backend job queues, and in extreme cases trigger out-of-memory conditions that take the instance offline. The available information indicates no direct confidentiality or integrity impact.

Mitigation

If you can’t patch tonight, do this now.

As a defense-in-depth measure, enable and tune User and IP rate limits for GitLab, which GitLab notes are disabled by default. Restrict public exposure of self-managed GitLab instances where feasible, especially access to the /api/graphql endpoint from untrusted networks. Upstream filtering, reverse-proxy rate limiting, WAF throttling, and network ACLs can reduce exploitability until patching is completed, but these measures are mitigations only and do not replace upgrading to a fixed version.

Remediation

Patch, then assume compromise.

Upgrade self-managed GitLab CE/EE instances to a fixed release: 18.10.3, 18.9.5, or 18.8.9 or later, depending on the supported upgrade path. GitLab states these releases contain the fix that adds controls to validate and constrain the quantity of GraphQL queries that an unauthenticated user can issue. GitLab.com and GitLab Dedicated were already patched at disclosure. GitLab also noted that versions 18.10.2, 18.9.4, and 18.8.8 were skipped and no packages exist for those version numbers.
PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType
GitLabGitlabapplication

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What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity7

Community discussion across Reddit, Mastodon, and other social sources.