CVE-2026-81991: Adobe Acrobat Reader out-of-bounds read in memory parsing

CVE-2026-81991 · Severity: medium · CVSS 5.5 · Published 2026-09-08

Adobe Acrobat Reader contains an out-of-bounds read vulnerability that could allow an attacker to access sensitive information from the application's memory. An attacker would need to trick a user into opening a specially crafted malicious PDF file to exploit this vulnerability. Successful exploitation could result in the disclosure of confidential data such as passwords, encryption keys, or other sensitive information stored in memory.

Technologies: Adobe Acrobat, Adobe Acrobat Reader, Adobe Acrobat Dc, Adobe Acrobat Reader Dc, Apple macOS, Microsoft Windows. Vendors: Adobe, Apple, Microsoft.

Quick answers

Is CVE-2026-81991 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-81991 being exploited in the wild.
How severe is CVE-2026-81991?
Medium severity, with a CVSS score of 5.5, published 8 September 2026.
Which products and versions are affected?
Adobe Acrobat Reader.
Is there a fix for CVE-2026-81991?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-81991 attacked?
It is attacked with local access, in a software library.
Am I affected by CVE-2026-81991?
Check whether you run Adobe Acrobat, Adobe Acrobat Reader, Adobe Acrobat Dc or one of the others listed. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The vulnerability is an out-of-bounds read flaw in Acrobat Reader's memory parsing logic. An attacker can craft a malicious PDF file that triggers the out-of-bounds read when processed by the application, potentially exposing sensitive data from adjacent memory regions. The attack vector requires user interaction—specifically, a victim must open and process the malicious PDF file. The vulnerability allows information disclosure but does not directly enable code execution or other higher-impact attacks. Patches are expected to be available through Adobe's security updates.

Affected products

  • Adobe Acrobat Reader

Timeline

  • 2026-09-08: disclosed

References

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