Out-of-bounds Read in Pjsip Pjproject

CVE-2026-34235

PJSIP is a free and open source multimedia communication library written in C. Prior to version 2.17, a heap out-of-bounds read vulnerability exists in PJSIP's VP9 RTP unpacketizer that occurs when parsing crafted VP9 Scalability Structure (SS) data. Insufficient bounds checking on the payload descriptor length may cause reads beyond the allocated RTP payload buffer. This issue has been patched in version 2.17. A workaround for this issue involves disabling VP9 codec if not needed.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

EPSS exploit prediction

EPSS: 0.004 (36.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 36th percentile — 36.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-34235: held from 0.005 to 0.004.

EPSS over last 30 days · oldest: 0.005 · newest: 0.004 · change: -0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-34235?
CVE-2026-34235 is a critical-severity vulnerability in Pjsip Pjproject, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2026-03-31.
How severe is CVE-2026-34235?
Critical severity. CVSS v3 base score is 9.1 out of 10.