CVE-2026-121944

sngrep through 1.9.0 Infinite Loop DoS via Crafted NFLOG TLV

CVSS score

6.8

EPSS probability

—

Risk score

0.7

Published

3 h ago

Overview Public Exploits (0)Newsroom Vulnerability Timeline

Patch status has not yet been verified

Resmî kaynaklarda yeterli kanıt bulunamadı. Bu sonuç “yama yok” anlamına gelmez.

Impact on My Inventory

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Vulnerability description

DayBreach AI Explanation

Verified against sources

Security Bulletin for CVE-2026-121944

Sources read

Source agreement

Tam uyum

Evidence confidence

%55

Short explanation

irontec sngrep through 1.9.0 contains an infinite loop vulnerability in capture_packet_reasm_ip() within src/capture.c, allowing attackers to cause denial of service via crafted NFLOG TLVs.

Why does it matter?

Attackers can cause the capture thread to spin at full CPU and stop processing packets by supplying a crafted pcap file.

What should be done?

Follow vendor advisories and official announcements

Chain of evidence and sources2 verified claims

irontec sngrep 1.9.0 ve önceki sürümler, hazırlanan NFLOG TLV girdileri nedeniyle sonsuz döngü zafiyeti içermektedir.

S0 · daybreach-canonical S1 · cvelist

Zafiyet, yakalama iş parçacığının tam CPU tüketmesine ve paket işlemeyi durdurmasına neden olur.

S0 · daybreach-canonical S1 · cvelist

Show the technical text from the sources

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

CWE: CWE-835

This explanation was compiled automatically from the source records. Scores, active exploitation, patch and exploit status come straight from the sources.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-121944 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

ID	VENDOR	PRODUCT	ACTION
1	irontec	sngrep	View

Total affected vendors: 1|Products: 1

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCORE	VERSION	SEVERITY	VECTOR	SOURCE
6.8	CVSS V4_0	MEDIUM	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	CVE CNA
6.8	CVSS V40	MEDIUM	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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X	NVD
5.5	CVSS V3_1	MEDIUM	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H	CVE CNA
5.5	CVSS V31	MEDIUM	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H	NVD

Patch and Remediation Guide

Solution & Remediation Advisory

Patch status unknown

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Confirm the affected product and version against the source evidence above.

Restrict access to internet-facing services and apply network segmentation.

Until a patch is confirmed, follow the vendor advisory; do not read an unknown status as “no patch”.

Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-121944 is associated with the following CWEs:

CWE-835: Common Weakness Enumeration Entry CWE-835

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-121944 weaknesses.

CAPEC-66: SQL Injection CAPEC-126: Path Traversal CAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureYerel erişim

PermissionsGerekmiyor

User—

Official Sources and Advisories

https://github.com/irontec/sngrep/issues/589vendor-advisory https://hackmd.io/@haindpwn/sngrep-sip-payload-missing-nul-oob-readvendor-advisory https://github.com/irontec/sngrep/blob/v1.9.0/src/capture.c#L581-L598vendor-advisory VulnCheck Advisory: sngrep through 1.9.0 Infinite Loop DoS via Crafted NFLOG TLVvendor-advisory

CVSS Vector Radar Chart

6.8 / 10

Vulnerability Scoring Details

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

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredNone required

User InteractionP

Confidentiality (Gizlilik)Low

Integrity (Bütünlük)P

Availability (Erişilebilirlik)High

Yama durumu bilinmiyor

İncelenen resmî kaynaklarda yama durumu doğrulanamadı. Bu sonuç “yama yok” anlamına gelmez.

Follow the vendor

irontec

Weakness Type (CWE & CAPEC)

CWE-835

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