CVE-2024-50039

Local host crash via nested TCA_STAB acceptance

Published Oct 21, 2024 · Updated Aug 5, 2026

Linux kernel traffic-control handling allows local users to crash the host through a crafted TBF and SFQ qdisc hierarchy. The qdisc parser accepts a TCA_STAB size table on the child SFQ even though backlog accounting assumes packet length stays invariant between enqueue and dequeue. A local user can obtain CAP_NET_ADMIN inside an unprivileged user namespace, underflow SFQ queue state, and trigger a NULL dereference during reset; the kernel CNA also identifies out-of-bounds memory access and heap-corruption primitives.

CVSS severity7.8
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Linux kernel traffic-control handling allows local users to crash the host through a crafted TBF and SFQ qdisc hierarchy. The qdisc parser accepts a TCA_STAB size table on the child SFQ even though backlog accounting assumes packet length stays invariant between enqueue and dequeue. A local user can obtain CAP_NET_ADMIN inside an unprivileged user namespace, underflow SFQ queue state, and trigger a NULL dereference during reset; the kernel CNA also identifies out-of-bounds memory access and heap-corruption primitives.

The record

CVE
CVE-2024-50039
Published
Oct 21, 2024
Updated
Aug 5, 2026
Vendor
Siemens
Product
SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 21, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <V3.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Siemens · SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 familyversion=0 <V3.2
Siemens · SIMATIC S7-1500 TM MFP - GNU/Linux subsystemversion=0 <*
The Linux Kernel Organization · Linuxversion=175f9c1bba9b825d22b142d183c9e175488b260c <1edf039ee01788ffc25625fe58a903ae2efa213e; version=175f9c1bba9b825d22b142d183c9e175488b260c <2acbb9539bc2284e30d2aeb789c3d96287014264; version=175f9c1bba9b825d22b142d183c9e175488b260c <3cb7cf1540ddff5473d6baeb530228d19bc97b8a; version=175f9c1bba9b825d22b142d183c9e175488b260c <3dc6ee96473cc2962c6db4297d4631f261be150f; version=175f9c1bba9b825d22b142d183c9e175488b260c <76feedc74b90270390fbfdf74a2e944e96872363; version=175f9c1bba9b825d22b142d183c9e175488b260c <8fb6503592d39065316f45d267c5527b4e7cd995; version=175f9c1bba9b825d22b142d183c9e175488b260c <adbc3eef43fc94c7c8436da832691ae02333a972; version=2.6.27
Siemens · SCALANCE XCM/XRM/XCH/XRH-300 familyversion=0 <V3.2
Siemens · RUGGEDCOM RST2428Pversion=0 <V3.2

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8Linux kernel CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5Siemens ProductCERTCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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