CVE-2026-121944 PUBLISHED

sngrep through 1.9.0 Infinite Loop DoS via Crafted NFLOG TLV

Assigner: VulnCheck
Reserved: 04.11.2026 Published: 04.11.2026 Updated: 04.11.2026

sngrep through 1.9.0 contains an infinite loop vulnerability in capture_packet_reasm_ip() in src/capture.c that allows attackers to cause denial of service via crafted NFLOG TLVs. Attackers can supply a pcap file with link type NFLOG containing a non-payload TLV with length under 4, making the capture thread spin at full CPU and stop processing packets.

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS Score: 6.8

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
CVSS Score: 5.5

Attack Vector	Local	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	Required	Availability Impact	High

CVSS 3.1

Product Status

Vendor	irontec
Product	sngrep
Versions	Default: unaffected affected from 0 to 1.9.0 (incl.)

CVE-2026-121944 PUBLISHED

sngrep through 1.9.0 Infinite Loop DoS via Crafted NFLOG TLV

Metrics

Product Status

Credits

References

Problem Types