CVE-2026-45771: Freeswitch Denial-of-Service in SIP PUBLISH Requests via XML Entity Expansion
FreeSWITCH is a Software Defined Telecom Stack enabling the digital transformation from proprietary telecom switches to a software implementation that runs on any commodity hardware. Prior to version 1.11.0, FreeSWITCH's bundled XML parser expands nested <!ENTITY> declarations without a depth or count bound, so a small DTD can describe a body that expands exponentially ("billion laughs"). The PIDF body of a SIP PUBLISH is fed to this parser before any digest check, letting an unauthenticated network attacker force unbounded CPU and memory consumption with a single request. This issue has been patched in version 1.11.0.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
freeswitchto a version that resolves this vulnerability.Fixed in 1.11.0
Event History
Frequently Asked Questions
What is the severity of CVE-2026-45771?
The severity of CVE-2026-45771 is classified as high with a score of 7.5.
How do I fix CVE-2026-45771?
To fix CVE-2026-45771, update FreeSWITCH to version 1.11.0 or later.
What type of issue is CVE-2026-45771?
CVE-2026-45771 is a denial-of-service vulnerability that affects the XML parsing in FreeSWITCH.
What impact does CVE-2026-45771 have on FreeSWITCH?
CVE-2026-45771 can lead to a denial of service condition by exploiting SIP PUBLISH requests.
Is my version of FreeSWITCH affected by CVE-2026-45771?
Versions of FreeSWITCH prior to 1.11.0 are affected by CVE-2026-45771.