CVE-2009-3459
CVE-2009-3459 is a security flaw in Adobe Acrobat and Reader, Adobe’s software for opening and editing PDFs. Opening a booby-trapped file can let an attacker run their own code through Adobe Acrobat and Reader. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 20 May 2026.[1]
Adobe Acrobat and Reader is in things households have, such as phones, computers, browsers and everyday apps, so the fix matters at home as much as at work. Adobe has published a fix or advice.
Description
CISA calls it a heap-based buffer overflow in Adobe Acrobat and Reader. In its words: “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.”[1]
The CVE record adds: “Heap-based buffer overflow in Adobe Reader and Acrobat 7.x before 7.1.4, 8.x before 8.1.7, and 9.x before 9.2 allows remote attackers to execute arbitrary code via a crafted PDF file that triggers memory corruption, as exploited in the wild in October 2009. NOTE: some of these details are obtained from third party information.”[2]
The underlying weakness is memory buffer error (CWE-119), in MITRE’s list of common software weaknesses.
It scores 8.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by the organisation that published the CVE using CVSS 3.1.[2]
Affected versions
NVD’s record doesn’t list version ranges for it; Adobe’s advisory has them[3]. CISA names the product as Adobe Acrobat and Reader.
Every device with Adobe Acrobat and Reader needs the update.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 20 May 2026, 6,063 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 3 Jun 2026 to fix it.[1]
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 87%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as not automatable: each attack takes some work.
CISA doesn’t say who was attacked, or how.
Fix
Adobe has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.”[1]
- Update Adobe Acrobat and Reader now.Install the latest update from Adobe on every device that has it, and restart when asked. Then turn on automatic updates, so the next fix arrives on its own.
- If there’s no update, stop using it.CISA’s advice when a flaw being used in attacks has no fix is to stop using the product until it does.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 8.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 87%.[4] |
See also
Other Adobe Acrobat and Reader flaws
- CVE-2026-34621: prototype pollution ·
- CVE-2023-21608: use-after-free ·
- CVE-2023-26369: out-of-bounds write ·
- CVE-2018-4990: double free ·
- CVE-2010-2883: stack-based buffer overflow ·
- CVE-2009-4324: use-after-free ·
Other Adobe flaws
- CVE-2026-48356, Adobe Commerce and Magento: unrestricted upload of file with dangerous type ·
- CVE-2026-71362, Adobe Commerce and Magento: incorrect authorization ·
- CVE-2026-75650, Adobe Commerce and Magento: improper neutralization of special elements used in a template engine ·
- CVE-2026-48282, Adobe ColdFusion: path traversal ·
- CVE-2020-9715, Adobe Acrobat: use-after-free ·
Other memory buffer error flaws
- CVE-2026-88779, Citrix NetScaler: improper restriction of operations within the bounds of a memory buffer ·
- CVE-2026-88772, Citrix NetScaler: improper restriction of operations within the bounds of a memory buffer ·
- CVE-2026-88771, Citrix NetScaler: improper input validation ·
- CVE-2026-8452, Citrix NetScaler ADC and NetScaler Gateway: improper restriction of operations within the bounds of a memory buffer ·
- CVE-2025-31277, Apple devices: buffer overflow ·
Added the same day
- CVE-2026-45498, Microsoft Defender: denial of service ·
- CVE-2026-41091, Microsoft Defender: link following ·
- CVE-2010-0806, Microsoft Internet Explorer: use-after-free ·
- CVE-2010-0249, Microsoft Internet Explorer: use-after-free ·
- CVE-2009-1537, Microsoft DirectX: NULL byte overwrite ·
Every Adobe flaw on CISA’s list · Everything added in May 2026
References
- ^ Cybersecurity and Infrastructure Security Agency. “Adobe Acrobat and Reader Heap-Based Buffer Overflow Vulnerability”. Known Exploited Vulnerabilities Catalog, added 20 May 2026.
- ^ National Institute of Standards and Technology. “CVE-2009-3459 Detail”. National Vulnerability Database, published 13 Oct 2009.
- ^ Adobe. Advisories and fixes: web.archive.org.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.866, percentile 99.7, 31 Oct 2026.
- CVE Program. “CVE-2009-3459”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.