BlackTreeCVE Intelligencesignalwire · freeswitch
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
High technical severity; prioritise exposed affected systems while verifying vendor guidance.
Mitigation availableFreeSWITCH 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.
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.
The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
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.
The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.
An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion'). The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
Operational remediation based on structured source evidence.
Published 9 Jun 2026 · Last source change 9 Jun 2026, 18:24 UTC · CWE-776 · Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
Core structured fields are present and their contributing authorities are shown above.
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.