How to check if you are exposed to CVE-2021-28550
- Find every Adobe Acrobat and Reader system you or your clients run, including ones exposed to the internet. Those come first: CISA only lists flaws attackers are already using.
- Compare each version with the fixed versions in the vendor advisory. Where no fix exists yet, apply the vendor’s mitigation or take the system off the internet.
- Run a credentialed vulnerability scan to catch the systems you missed, then check that the next scan no longer reports CVE-2021-28550.
US federal agencies had to fix this by 2021-11-17. Everyone else should treat that deadline as a guide: if it has passed, this is overdue.
Timeline
- · Added to CISA's Known Exploited Vulnerabilities catalog
- · Fix-by date for US federal agencies, passed 1,810 days ago
Weakness type
More exploited Adobe vulnerabilities
CISA lists 83 exploited Adobe vulnerabilities. The closest matches:
- CVE-2009-3459Adobe Acrobat and Reader Heap-Based Buffer Overflow VulnerabilityAdded 2026-05-20
- CVE-2026-34621Adobe Acrobat and Reader Prototype Pollution VulnerabilityAdded 2026-04-13
- CVE-2023-21608Adobe Acrobat and Reader Use-After-Free VulnerabilityAdded 2023-10-10
- CVE-2023-26369Adobe Acrobat and Reader Out-of-Bounds Write VulnerabilityAdded 2023-09-14
- CVE-2018-4990Adobe Acrobat and Reader Double Free VulnerabilityAdded 2022-06-08
- CVE-2010-2883Adobe Acrobat and Reader Stack-Based Buffer Overflow VulnerabilityAdded 2022-06-08
- CVE-2009-4324Adobe Acrobat and Reader Use-After-Free VulnerabilityAdded 2022-06-08
- CVE-2009-3953Adobe Acrobat and Reader Universal 3D Remote Code Execution VulnerabilityAdded 2022-06-08
Keep going
Sources: CISA Known Exploited Vulnerabilities catalog (version 2026.10.30); EPSS data from FIRST.org; CVSS and descriptions from the NIST National Vulnerability Database. Checked 2026-11-01. This product uses the NVD API but is not endorsed or certified by the NVD.