Vulnerability · Published Aug 4, 2026 · Assigned by GitHub_M

CVE-2026-45705OpenSIPS: OOB Read in Multipart Body Boundary Parsing

Medium 5.3

In plain English

A medium-severity out-of-bounds read in opensips from OpenSIPS. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium
Exploit odds (30 days)0.5%top 56.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

OpenSIPS is a Session Initiation Protocol (SIP) server implementation. In versions prior to 3.6.6 and 4.0.0-rc1, the find_line_delimiter() 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 products (as reported)

VendorProductVersions
OpenSIPS opensips >= 3.4.0, < 3.6.6>= 4.0.0-beta, < 4.0.0-rc1

Weakness: CWE-125 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References