CVE-2026-32945: PJSIP is vulnerable to Heap-based Buffer Overflow through DNS parser

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-03-20 · updated 2026-06-17
Weakness: CWE-122

Description

PJSIP is a free and open source multimedia communication library written in C. Versions 2.16 and below have a Heap-based Buffer Overflowvulnerability in the DNS parser's name length handler. Thisimpacts applications using PJSIP's built-in DNS resolver, such as those configured with pjsua_config.nameserver or UaConfig.nameserver in PJSUA/PJSUA2. It does not affect users who rely on the OS resolver (e.g., getaddrinfo()) by not configuring a nameserver, or those using an external resolver via pjsip_resolver_set_ext_resolver(). This issue is fixed in version 2.17. For users unable to upgrade, a workaround is to disable DNS resolution in the PJSIP config (by setting nameserver_count to zero) or to use an external resolver implementation instead.

Affected products

Pjsip: before 2.17 — fixed in 2.17

How to fix

Upgrade to a fixed version: Pjsip 2.17. Check the vendor advisory for mitigations.

References

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