Monkeytype: fork PR can execute code with elevated GITHUB_TOKEN (monkeytypegame monkeytype)

CVE-2026-118762
CRITICAL 9.3

At a glance

Source
NVD
EPSS
EPSS 0.32 % · percentile 25 ()
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Deferred

Description

Monkeytype is a minimalistic and customizable typing test. Prior to 26.43.0, the .github/workflows/fix-formatting.yml workflow runs on pull_request_target with repository write permissions, checks out a fork pull request, installs dependencies from the fork's package.json, and invokes the fork-controlled oxfmt binary. Because actions/checkout persists the elevated GITHUB_TOKEN in Git configuration until after untrusted code executes, an external contributor whose pull request receives the format label can run arbitrary code, read or exfiltrate the token, and push repository content or modify pull requests and issues. The issue affects the repository CI workflow, not the Monkeytype application or user data. This issue is fixed in version 26.43.0.

Weaknesses (CWE)

  • CWE-829 — Inclusion of Functionality from Untrusted Control Sphere

References

Scores

VersionScoreVectorScored by
CVSS 3.1CRITICAL 9.3CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:NGitHub_M
CVSS 3.1CRITICAL 9.3CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:NNVD · security-advisories@github.com (Secondary)

European references

Affected products

ProductVersions
monkeytypegame · monkeytypeaffected < 26.43.0

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD