CVE-2026-28799
Description
A flaw was found in PJSIP. A remote attacker can exploit a heap use-after-free vulnerability within the event subscription framework by sending a specially crafted message during presence unsubscription. This can lead to a denial of service, making the affected system unavailable.
Statement
IMPORTANT: A heap use-after-free vulnerability in PJSIP's event subscription framework allows a remote attacker to cause a denial of service. This flaw is triggered by sending a specially crafted message during presence unsubscription, leading to system unavailability. Red Hat products utilizing PJSIP for presence functionality may be affected.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the expired pointer is used in a read operation, an attacker might be able to control data read in by the application.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the expired pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If the expired pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
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