What is CVE-2026-90778?

CVE-2026-90778 is a high-severity vulnerability in Sipp, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.5/10. Published 2026-09-13.

How severe is CVE-2026-90778?

High severity. CVSS v3 base score is 7.5 out of 10.

Buffer overflow in Sipp

CVE-2026-90778

SIPp through 3.7.7 contains a buffer overflow vulnerability in get_peer_tag() function when processing SIP To headers with tag parameters of 2049 bytes or more. Unauthenticated remote attackers can send crafted SIP messages with oversized tag parameters to overflow the static buffer and crash the process.

Vulnerability class: Buffer Overflow

Published 2026-09-13 · last modified 2026-09-23.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.009 (58.2th percentile), scored 2026-10-28.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Sipp

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

github.com/SIPp/sipp/pull/879 (issue-tracking, patch)
github.com/SIPp/sipp/commit/ddf22d1a54e0396b2e18ebaf4cf5a3fa860e5da4 (patch)
github.com/SIPp/sipp/blob/v3.7.7/src/sip_parser.cpp (technical-description)
github.com/SIPp/sipp (product)
www.vulncheck.com/advisories/sipp-through-3.7.7-buffer-overflow-via-sip-to-head… (third-party-advisory)

Frequently asked questions

What is CVE-2026-90778?: CVE-2026-90778 is a high-severity vulnerability in Sipp, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 7.5/10. Published 2026-09-13.
How severe is CVE-2026-90778?: High severity. CVSS v3 base score is 7.5 out of 10.