Is CVE-2026-26203 actively exploited?

CVE-2026-26203 has no public evidence of in-the-wild exploitation as of 2026-02-20.

What is the CVSS score for CVE-2026-26203?

CVE-2026-26203 has a CVSS score of 5.1 (MEDIUM severity). Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

How do I patch CVE-2026-26203?

Patch guidance is available from pjsip security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-26203.

CVE-2026-26203 - remediation guidance & executive summary

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.

CVSS Metrics

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector: local
Complexity: low
Privileges: none
User Action: none
Confidentiality: undefined
Integrity: undefined
Availability: undefined
Weaknesses: CWE-416 · Use After Free

Metadata

Primary Vendor: PJSIP
Published: 2/19/2026
Last Modified: 2/20/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

pjsip : pjsip

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-26203. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-26203

View on NIST NVD

CVE-2026-26203 vulnerability