CVE-2026-121943— Irontec sngrep through 1.9.0 Out-of-Bounds Stack Read via sip_check_packet

Quick assessment

Affected

irontec sngrep

Exploitation

No confirmed in-the-wild exploitation; assess based on exposure

Recommended action

Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Irontec sngrep 1.9.0 及更早版本存在一个越界栈读取漏洞，该漏洞位于和函数中，原因是针对 10240 字节 SIP 载荷的长度检查存在“差一”（off-by-one）错误。远程攻击者可发送精心构造的 UDP 或 TCP SIP 数据包，或提供恶意 PCAP 文件，从而导致 sngrep 崩溃，或将相邻的栈内存字节泄露到显示的 SIP 字段中。

CVSS 4.8 · Medium Updated Nov 05, 2026

Possible ATT&CK Techniques 1 AI

T1190 · Exploit Public-Facing Application

Affected Version Matrix 1

Vendor	Product	Version Range	Status
irontec	sngrep	`≤ 1.9.0`	affected

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Vulnerability Information

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Vulnerability Title

Irontec sngrep through 1.9.0 Out-of-Bounds Stack Read via sip_check_packet

Source: CVE Program / CVE List V5

Vulnerability 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.

Source: CVE Program / CVE List V5

CVSS Information

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

Source: CVE Program / CVE List V5

Vulnerability Type

不恰当的空终结符

Source: CVE Program / CVE List V5

Affected Products

Vendor	Product	Affected Versions	CPE	Subscribe
irontec	sngrep	0 ~ 1.9.0	-

II. Public POCs for CVE-2026-121943

#	POC Description	Source Link	Shenlong Link

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III. Intelligence Information for CVE-2026-121943

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Other References for CVE-2026-121943 (4)

https://github.com/irontec/sngrep/issues/589 issue-tracking
https://hackmd.io/@haindpwn/sngrep-sip-payload-missing-nul-oob-read third-party-advisory
https://github.com/irontec/sngrep/blob/v1.9.0/src/sip.c#L396-L410 technical-description
https://www.vulncheck.com/advisories/irontec-sngrep-through-1.9.0-out-of-bounds-stack-read-via-sip-check-packet third-party-advisory

https://www.cve.org/CVERecord?id=CVE-2026-121943

IV. Related Vulnerabilities

Same product: sngrep

Same vendor: irontec

Same weakness: CWE-170