DEBIAN-CVE-2026-121944: Debian/sngrep vulnerability

sngrep through 1.9.0 contains an infinite loop vulnerability in capturepacketreasmip() 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.