CVE-2026-81977: Adobe Acrobat Reader integer underflow in memory handling

CVE-2026-81977 · Severity: medium · CVSS 5.5 · Published 2026-09-08

Adobe Acrobat Reader contains an integer underflow vulnerability in its memory handling logic that could allow an attacker to disclose sensitive information from system memory. This vulnerability requires a user to open a malicious PDF file, making it a practical attack vector against organizations that exchange documents. Successful exploitation could expose confidential data stored in memory at the time of the attack.

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-2026-81977 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-81977 being exploited in the wild.
How severe is CVE-2026-81977?
Medium severity, with a CVSS score of 5.5, published 8 September 2026.
Which products and versions are affected?
Adobe Acrobat Reader <UNKNOWN>.
Is there a fix for CVE-2026-81977?
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-2026-81977 attacked?
It is attacked over the network.
Am I affected by CVE-2026-81977?
Check whether you run Adobe Acrobat, Adobe Acrobat Reader, Adobe Acrobat Dc or one of the others listed at an affected version. 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

An integer underflow (wrap or wraparound) vulnerability exists in Adobe Acrobat Reader's memory processing logic. The vulnerability occurs when an integer value wraps around during arithmetic operations, causing the application to allocate or access memory incorrectly. This flaw requires user interaction—specifically, opening a specially crafted malicious PDF file—to trigger the vulnerability. An attacker can exploit this to read sensitive information from process memory. No publicly known fix is available at this time based on the advisory information provided.

Affected products

  • Adobe Acrobat Reader <UNKNOWN>

Timeline

  • 2026-09-08: disclosed

References

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