Infinite Loop Denial of Service in sngrep by Irontec
CVE-2026-121944

6.8MEDIUM

Key Information:

Vendor

Irontec

Status
Sngrep
Vendor
CVE Published:
4 November 2026

What is CVE-2026-121944?

The sngrep tool, utilized for capturing network packets, is susceptible to an infinite loop vulnerability in the capture_packet_reasm_ip() function. This vulnerability can be exploited by attackers who craft specific NFLOG TLVs. By supplying a pcap file containing a non-payload TLV with a length under 4, an attacker can induce the capture thread to enter a state of excessive CPU usage, effectively stopping it from processing legitimate packets and leading to service unavailability.

Affected Version(s)

sngrep 0 <= 1.9.0

References

https://github.com/irontec/sngrep/issues/589
issue-tracking
https://hackmd.io/@haindpwn/sngrep-sip-payload-missing-nu...
third-party-advisory
https://github.com/irontec/sngrep/blob/v1.9.0/src/capture...
technical-description

CVSS V4

Score:
6.8
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

HaiND from the Post and Telecommunication Institute of Technology
.