CVE-2026-121943
Deferred Deferred - Pending Action

Out-of-Bounds Stack Read in Irontec sngrep

Publication date: 2026-11-04

Last updated on: 2026-11-04

Assigner: VulnCheck

Description
Irontec sngrep through 1.9.0 contains an out-of-bounds stack read vulnerability in sip_check_packet and sip_validate_packet caused by an off-by-one length check on 10240-byte SIP payloads. Remote attackers can send a crafted UDP or TCP SIP packet or supply a pcap file to crash sngrep or leak adjacent stack bytes into displayed SIP fields.

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Meta Information

Published
2026-11-04
Last Modified
2026-11-04
Generated
2026-11-04
AI Q&A
2026-11-04
EPSS Evaluated
N/A
NVD
CVE-2026-121943
EUVD
EUVD-2026-116900

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
irontec sngrep 0

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-170 The product does not terminate or incorrectly terminates a string or array with a null character or equivalent terminator.

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Executive Summary

CVE-2026-121943 is an out-of-bounds stack read vulnerability in Irontec sngrep through version 1.9.0. It occurs in the SIP message parsing functions sip_check_packet and sip_validate_packet due to an off-by-one error when handling 10240-byte SIP payloads. Attackers can send crafted UDP or TCP SIP packets or pcap files to crash sngrep or leak adjacent stack memory into displayed SIP fields.

Detection Guidance

To detect this vulnerability, monitor for crashes in sngrep when processing SIP packets or pcap files. Check for abnormal memory usage or stack corruption in logs. Use network monitoring tools to inspect SIP traffic for malformed packets exceeding standard payload sizes.

Impact Analysis

This vulnerability can cause sngrep to crash, leading to denial-of-service conditions. It may also expose sensitive stack memory, potentially leaking information. Exploitation requires no authentication and can be triggered via network packets or malicious pcap files.

Mitigation Strategies

Immediately upgrade sngrep to a patched version beyond 1.9.0. If upgrading is not possible, restrict network access to sngrep or disable SIP packet capture features. Monitor for suspicious SIP traffic patterns and block malformed packets at the network perimeter.

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