Widely deployed Acrobat Reader; RCE via malicious file; high risk.
CVE-2026-34621
Prototype Pollution in Acrobat Reader enables arbitrary code execution via malicious file.
Is CVE-2026-34621 being exploited?
Yes. CVE-2026-34621 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2026-34621?
CVE-2026-34621 is rated High with a CVSS score of 8.6. 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-2026-34621?
Yes. A fix has been recorded for CVE-2026-34621. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-34621 affect?
CVE-2026-34621 affects Adobe Acrobat Reader DC <= 26.001.21367 (including 24.001.30356). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-34621?
Update to the latest Acrobat Reader version.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
RCE in the current user context via crafted document; user interaction required.
Patch when possible
- affected<= 24.001.30356
- affected<= 26.001.21367
- affected<= 26.001.21367
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.