CVE-2026-110598 libyal CVE debrief

Who should care

Defenders responsible for systems and applications using libpff should assess exposure and take action to prevent exploitation. This includes reviewing version information, updating to a fixed version if available, monitoring for suspicious activity, and implementing compensating controls.

Why it matters

The CVE-2026-110598 vulnerability in libpff allows attackers to trigger heap out-of-bounds reads, potentially leading to crashes, denial of service attacks, and exposure of sensitive information. Defenders responsible for systems and applications using libpff should assess exposure and take action to prevent exploitation.

• Potential crash of libpff, pypff, or pffexport
• Exposure of adjacent heap memory
• Possible denial of service (DoS) attacks
• Potential for attackers to gain information about the heap layout

Technical summary

The libpff library through version 20260926 contains an integer underflow in the libpff_record_entry_get_multi_value() function. This vulnerability allows attackers to trigger heap out-of-bounds reads via non-monotonic multi-value offsets. Attackers can craft PST, OST, or PAB files with decreasing PT_MV_STRING8, PT_MV_UNICODE, or PT_MV_BINARY offsets to crash libpff, pypff, or pffexport and expose adjacent heap memory.

Defensive priority

Medium

Recommended defensive actions

• Review and assess exposure of systems and applications using libpff
• Verify version information for libpff and update to a fixed version if available
• Monitor for suspicious activity and implement compensating controls
• Consider implementing additional security measures to prevent exploitation
• Perform a thorough review of system configurations and asset inventory
• Establish a process for tracking and addressing exceptions
• Implement source tracking to monitor for potential exploitation attempts

Evidence notes

The CVE record and source item provide details on an integer underflow in libpff_record_entry_get_multi_value() that allows attackers to trigger heap out-of-bounds reads via non-monotonic multi-value offsets.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.