CVE-2026-90778 SIPp CVE debrief

Who should care

Defenders responsible for SIPp installations, network administrators, and security teams should be aware of this vulnerability and take necessary actions to prevent potential crashes and buffer overflow attacks.

Why it matters

CVE-2026-90778 is a buffer overflow vulnerability in SIPp that can cause crashes and potentially lead to denial-of-service conditions. Defenders should verify and update SIPp installations, monitor for potential attacks, and restrict access to trusted sources.

• Potential crashes of SIPp services
• Verification of SIPp installations and updates
• Monitoring for potential buffer overflow attacks
• Implementation of network restrictions to trusted sources

Technical summary

The get_peer_tag() function in SIPp is vulnerable to a buffer overflow when processing SIP To headers with tag parameters of 2049 bytes or more. This can be exploited by unauthenticated remote attackers to crash the process. The vulnerability affects SIPp through version 3.7.7 and has a CVSS score of 8.7, classified as HIGH severity. Defenders should prioritize verifying and updating SIPp installations to prevent potential crashes from buffer overflow attacks. Review of official advisories and CVE records is recommended for further details.

Defensive priority

Defenders should prioritize verifying and updating SIPp installations to prevent potential crashes from buffer overflow attacks.

Recommended defensive actions

• Verify and update SIPp installations to the latest version
• Implement network monitoring to detect potential buffer overflow attacks
• Restrict access to SIPp services to trusted sources
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the buffer overflow vulnerability in SIPp. The vulnerability is caused by improper handling of SIP To headers with large tag parameters. Defenders should verify SIPp installations, review official advisories, and monitor for potential attacks. Evidence is limited to public CVE and NVD records, which may not cover all affected versions or scenarios. Further verification is recommended.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.