CVE-2026-26203
Medium
Description
PJSIP is a free and open source multimedia communication library. Versions prior to 2.17 have a critical heap buffer underflow vulnerability in PJSIP's H.264 packetizer. The bug occurs when processing malformed H.264 bitstreams without NAL unit start codes, where the packetizer performs unchecked pointer arithmetic that can read from memory located before the allocated buffer. Version 2.17 contains a patch for the issue.
SeverityMedium
CVSS6.5
Exploit probability—
ProductPjsip
PublishedFeb 19, 2026
First seenFeb 19, 2026
Weakness typeCWE-416Use after free
How to fix
Update
- pjsip pjsip2.17 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| pjsip pjsip | v < 2.17 | 2.17 |
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