CVE-2026-90779

SIPp through 3.7.7 Stack Buffer Overflow via createAuthHeader Algorithm Parameter

Published Sep 13, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Description

SIPp through 3.7.7 contains a stack buffer overflow vulnerability in createAuthHeader() when processing SIP authentication challenges with oversized algorithm parameters. A malicious SIP server can send a crafted 401 or 407 challenge to corrupt the stack and crash the client process.

Analysis

Technical impact

SIPp through version 3.7.7 includes a stack buffer overflow in the createAuthHeader() routine that is triggered when processing SIP authentication challenges with oversized algorithm parameters. The vulnerability can be exercised by a malicious SIP server sending a crafted 401 or 407 challenge. The overflow corrupts the client’s stack and leads to a crash, resulting in a denial‑of‑service outcome.

Affected Systems

The affected product is SIPp, the open‑source SIP testing tool. All releases up to and including version 3.7.7 are vulnerable; newer releases patch the issue.

Risk and Exploitability

The CVSS score is 8.7, indicating a severe vulnerability. The EPSS score is < 1%, and the CVE is not listed in the CISA KEV catalogue, so the exact exploitation likelihood is unknown, but the vulnerability can be triggered by any SIP server that the client communicates with. An attacker with network visibility can send a crafted challenge to a vulnerable SIPp client to force a crash and disrupt service.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

SIPp

sipp

unaffected

Version	Status	Constraints
`0`	affected	≤ 3.7.7

No data.

Vendor Product Versions

Sipp

Version	Status	Scheme	Platform
`[0,3.7.7]`	affected	generic	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Update SIPp to version 3.7.8 or later, which includes the patch for the buffer overflow.
Configure SIPp or upstream devices to reject authentication challenges whose algorithm parameter length exceeds the normal maximum, preventing oversized values from reaching the application.
Deploy network monitoring or IDS/IPS rules to detect and block SIP 401/407 messages that violate RFC 3261 by containing unusually long algorithm fields, and configure the service to automatically restart if it crashes to reduce downtime.

Generated by OpenCVE AI on September 15, 2026 at 16:54 UTC.

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.802% probability within 30 days)

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
https://github.com/SIPp/sipp
https://github.com/SIPp/sipp/blob/v3.7.7/src/auth.cpp#L183-L192
https://github.com/SIPp/sipp/commit/1d4a5622bea34d0b5cdff333e6b5734608e30af7
https://github.com/SIPp/sipp/pull/880
https://www.vulncheck.com/advisories/sipp-through-3.7.7-stack-buffer-overflow-via-createauthheader-algorithm-parameter

History

Sep 14, 2026 9:00 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Sep 13, 2026 1:45 PM First appearance in the feed. Affected vendors updated View changes

Type	Values Removed	Values Added
First Time appeared		Sipp Sipp sipp
Vendors & Products		Sipp Sipp sipp

Sep 13, 2026 11:45 AM Description updated. Title updated. Weaknesses updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		SIPp through 3.7.7 contains a stack buffer overflow vulnerability in createAuthHeader() when processing SIP authentication challenges with oversized algorithm parameters. A malicious SIP server can send a crafted 401 or 407 challenge to corrupt the stack and crash the client process.
Title		SIPp through 3.7.7 Stack Buffer Overflow via createAuthHeader Algorithm Parameter
Weaknesses		CWE-121
References		https://github.com/SIPp/sipp https://github.com/SIPp/sipp/blob/v3.7.7/src/auth.cpp#L183-L192 https://github.com/SIPp/sipp/commit/1d4a5622bea34d0b5cdff333e6b5734608e30af7 https://github.com/SIPp/sipp/pull/880 https://www.vulncheck.com/advisories/sipp-through-3.7.7-stack-buffer-overflow-via-createauthheader-algorithm-parameter
Metrics		cvssV3_1 `{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}` cvssV4_0 `{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}`