Exploited vulnerability · CISA KEV
Yes. CVE-2009-3459, Adobe Acrobat and Reader Heap-Based Buffer Overflow Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 20 May 2026, 6063 days after it was published. It affects Adobe Acrobat and Reader. If you run it, CISA's required action is: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Adobe Acrobat and Reader contain a heap-based buffer overflow vulnerability which could allow remote attackers to execute arbitrary code via a crafted PDF file that triggers memory corruption.
| Vendor | Adobe (83 exploited CVEs in KEV) |
| Product | Acrobat and Reader |
| Vulnerability | Adobe Acrobat and Reader Heap-Based Buffer Overflow Vulnerability |
| Weakness | CWE-119 |
| Published | 13 Oct 2009 |
| Added to KEV | 20 May 2026 |
| Reported by (CNA) | adobe |
Yes. CISA added CVE-2009-3459 to the Known Exploited Vulnerabilities catalog on 20 May 2026, which means there is reliable evidence of exploitation in the wild.
CISA does not list known ransomware use for it. That can change, and exploitation alone is reason to fix it first.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Check Adobe's advisory for the fixed versions, and if you can't patch quickly, restrict access to the affected Acrobat and Reader and watch it for signs of compromise.
Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in May 2026 · Adobe scorecard · act-now radar.
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