Vulnerability in Irontec Sngrep
CVE-2026-121943
Irontec sngrep through 1.9.0 contains an out-of-bounds stack read vulnerability in sip_check_packet and sip_validate_packet caused by an off-by-one length check on 10240-byte SIP payloads. Remote attackers can send a crafted UDP or TCP SIP packet or supply a pcap file to crash sngrep or leak adjacent stack bytes into displayed SIP fields.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/irontec/sngrep/issues/589 (issue-tracking)
- hackmd.io/@haindpwn/sngrep-sip-payload-missing-nul-oob-read (third-party-advisory)
- github.com/irontec/sngrep/blob/v1.9.0/src/sip.c (technical-description)
- www.vulncheck.com/advisories/irontec-sngrep-through-1.9.0-out-of-bounds-stack-r… (third-party-advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0
Frequently asked questions
- What is CVE-2026-121943?
- CVE-2026-121943 is a medium-severity vulnerability in Irontec Sngrep, classified under Improper Null Termination. CVSS score: 4.8/10. Published 2026-11-04.
- How severe is CVE-2026-121943?
- Medium severity. CVSS v3 base score is 4.8 out of 10.