CVE-2026-45705: OpenSIPS: OOB Read in Multipart Body Boundary Parsing
OpenSIPS is a Session Initiation Protocol (SIP) server implementation. In versions prior to 3.6.6 and 4.0.0-rc1, the findlinedelimiter() function in the multipart body parser performs an out-of-bounds read via strncmp() when searching for MIME boundary delimiters. After finding a -- pattern near the end of the body, the function compares delimiter.len bytes (typically 20-70) starting from a position at or past the logical end of the body buffer, reading past the body boundary. The bug triggers when a SIP message has Content-Type: multipart/mixed with a boundary parameter and its body contains -- within two to three bytes of the body's end without being followed by the actual boundary delimiter. This issue has been fixed in versions 3.6.6 and 4.0.0-rc1.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
OpenSIPSto a version that resolves this vulnerability.Fixed in 3.6.6 - Upgrade
Upgrade
OpenSIPSto a version that resolves this vulnerability.Fixed in 4.0.0-rc1
Event History
Frequently Asked Questions
What is the severity of CVE-2026-45705?
CVE-2026-45705 has a medium severity rating of 5.3.
How do I fix CVE-2026-45705?
To fix CVE-2026-45705, update OpenSIPS to version 3.6.6 or later, or to 4.0.0-rc1.
What type of vulnerability is CVE-2026-45705?
CVE-2026-45705 is an out-of-bounds read vulnerability in the multipart body boundary parsing function.
Which versions of OpenSIPS are affected by CVE-2026-45705?
OpenSIPS versions prior to 3.6.6 and 4.0.0-rc1 are affected by CVE-2026-45705.
What impact does CVE-2026-45705 have on OpenSIPS?
The impact of CVE-2026-45705 includes potential information leakage due to out-of-bounds read in the MIME boundary parsing.