Buffer overflow in Pjsip Pjproject

CVE-2026-40614

PJSIP is a free and open source multimedia communication library written in C. In 2.16 and earlier, there is a buffer overflow when decoding Opus audio frames due to insufficient buffer size validation in the Opus codec decode path. The FEC decode buffers (dec_frame[].buf) were allocated based on a PCM-derived formula: (sample_rate/1000) * 60 * channel_cnt * 2. At 8 kHz mono this yields only 960 bytes, but codec_parse() can output encoded frames up to MAX_ENCODED_PACKET_SIZE (1280) bytes via opus_repacketizer_out_range(). The three pj_memcpy() calls in codec_decode() copied input->size bytes without bounds checking, causing a heap buffer overflow.

Vulnerability class: Buffer Overflow

EPSS: 0.002 (13.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40614?
CVE-2026-40614 is a high-severity vulnerability in Pjsip Pjproject, classified under Heap-based Buffer Overflow. CVSS score: 8.8/10. Published 2026-04-21.
How severe is CVE-2026-40614?
High severity. CVSS v3 base score is 8.8 out of 10.