CVE-2026-53507
SSRF in oasdiff-action allowed external $ref fetches from PRs, exposing runner files.
Is CVE-2026-53507 being exploited?
Not confirmed. CVE-2026-53507 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.29% probability of exploitation in the next 30 days.
How severe is CVE-2026-53507?
CVE-2026-53507 is rated High. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-53507?
Yes. A fix has been recorded for CVE-2026-53507. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-53507 affect?
CVE-2026-53507 affects oasdiff-action < 0.0.51, GitHub Actions runners, Repositories using oasdiff-action in workflows. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-53507?
Upgrade oasdiff-action to >=0.0.51 and block running untrusted PR workflows.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Attacker-controlled PRs can trigger SSRF and read files on GitHub Actions runners, enabling secret disclosure and internal endpoint access.
Immediate action required
- affected< 0.0.51
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.