sngrep through 1.9.0 Infinite Loop DoS via Crafted NFLOG TLV
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- Proof of concept public, per CISA
- Fix
- No fix listed
- Who is exposed
- Not reported
- Exploitation15/40CISA rates a proof of concept as public
- Exposure?/25Exposure: unknown (data gap). No advisory context yet
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity6.8/10CVSS 6.8
- No patch5/5No patch listed yet
What would change the score
- Would score about 67 if added to CISA KEV
- Would score about 62 if CISA's SSVC rates exploitation active
- Would score about 49 if advisories confirm default setups are exposed
CVE-2026-121944 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 6.8 (medium) and affects sngrep; no fixed version is listed yet.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 27/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: poc
- Automatable: no
- Technical impact: partial
Summary
Sngrep through 1.9.0 has an infinite loop flaw in its packet capture code that a local attacker can trigger by supplying a crafted pcap file with NFLOG link type, causing a denial of service where the capture thread uses full CPU and stops processing packets. The attack requires no login but does need the user to open the malicious file.
Read the original description
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.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: poc · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- irontec sngrep
through 1.9.0
Evidence 5
- Exploit
- Report
- Repository
- Link
- Link
Corrections
None so far.
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Questions about CVE-2026-121944
Is CVE-2026-121944 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. CISA's SSVC assessment notes a proof of concept exists. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-121944?
sngrep: through 1.9.0.Source: cve.now feed data