Buffer overflow in Pjsip Pjproject

CVE-2026-40892

PJSIP is a free and open source multimedia communication library written in C. In 2.16 and earlier, a stack buffer overflow exists in pjsip_auth_create_digest2() in PJSIP when using pre-computed digest credentials (PJSIP_CRED_DATA_DIGEST). The function copies credential data using cred_info->data.slen as the length without an upper-bound check, which can overflow the fixed-size ha1 stack buffer (128 bytes) if data.slen exceeds the expected digest string length.

Vulnerability class: Buffer Overflow

EPSS: 0.004 (35.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-40892?
CVE-2026-40892 is a critical-severity vulnerability in Pjsip Pjproject, classified under Stack-based Buffer Overflow. CVSS score: 9.8/10. Published 2026-04-21.
How severe is CVE-2026-40892?
Critical severity. CVSS v3 base score is 9.8 out of 10.