High severity · published Mar 6, 2026
CVE-2026-28799
PJSIP: Heap use-after-free in PJSIP presence subscription termination handler
7.5
CVSS
0.3%
EPSS
No
On KEV
Description
PJSIP is a free and open source multimedia communication library written in C. Prior to version 2.17, a heap use-after-free vulnerability exists in PJSIP's event subscription framework (evsub.c) that is triggered during presence unsubscription (SUBSCRIBE with Expires=0). This issue has been patched in version 2.17.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 22% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PJ
pjproject · pjsip
< 2.17 · source: vendor
PJ
Pjsip · Pjsip
before 2.17 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-28799
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-28799
Patch
https://github.com/pjsip/pjproject/commit/e06ff6c64741cc1675fd3296615910f532f6b1a1
Patch
https://github.com/pjsip/pjproject/security/advisories/GHSA-8fj4-fv9f-hjpc
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