CVE-2026-45705

OpenSIPS: OOB Read in Multipart Body Boundary Parsing

MEDIUM
5.3
CVSS Score
Published: August 4, 2026 at 11:16 PM UTC
Updated: September 8, 2026 at 08:59 PM UTC
1 product affected across 1 vendorOpenSIPS

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.5%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.6.6v < 4.0.0-rc1
Affected range stops below 3.6.6, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.0.0-rc1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-125

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