CVE-2024-26863

Service interruption via untagged HSR frame parsing

Published Apr 17, 2024 · Updated May 12, 2026

Use of uninitialized data in Linux HSR networking allows local users to interrupt service by sending a malformed Ethernet frame. hsr_get_skb_sequence_nr() reads bytes as a sequence number when an ETH_P_HSR or ETH_P_PRP header lacks the required HSR tag, propagating an invalid value into hsr_get_node(). Reachability requires local access sufficient to transmit crafted link-layer frames through an active HSR path; no confidentiality or integrity impact is reported.

CVSS severity5.5
Medium
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

Use of uninitialized data in Linux HSR networking allows local users to interrupt service by sending a malformed Ethernet frame. hsr_get_skb_sequence_nr() reads bytes as a sequence number when an ETH_P_HSR or ETH_P_PRP header lacks the required HSR tag, propagating an invalid value into hsr_get_node(). Reachability requires local access sufficient to transmit crafted link-layer frames through an active HSR path; no confidentiality or integrity impact is reported.

The record

CVE
CVE-2024-26863
Published
Apr 17, 2024
Updated
May 12, 2026
Vendor
Siemens
Product
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP
Classifications
CWE-908, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 17, 2024CVE publishedPublication date reported by the CVE source.
  2. May 12, 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=V3.1.0 <V3.1.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Siemens · SIPLUS S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.0 <V3.1.5
Siemens · SIMATIC S7-1500 TM MFP - GNU/Linux subsystemversion=0 <*
The Linux Kernel Organization · Linuxversion=3.17; version=f266a683a4804dc499efc6c2206ef68efed029d0 <09e5cdbe2cc88c3c758927644a3eb02fac317209; version=f266a683a4804dc499efc6c2206ef68efed029d0 <1ed222ca7396938eb1ab2d034f1ba0d8b00a7122; version=f266a683a4804dc499efc6c2206ef68efed029d0 <39cc316fb3bc5e7c9dc5eed314fe510d119c6862; version=f266a683a4804dc499efc6c2206ef68efed029d0 <7fb2d4d6bb1c85f7a23aace0ed6c86a95dea792a; version=f266a683a4804dc499efc6c2206ef68efed029d0 <889ed056eae7fda85b769a9ab33c093379c45428; version=f266a683a4804dc499efc6c2206ef68efed029d0 <97d2148ea435dff4b4e71817c9032eb321bcd37e; version=f266a683a4804dc499efc6c2206ef68efed029d0 <a809bbfd0e503351d3051317288a70a4569a4949; version=f266a683a4804dc499efc6c2206ef68efed029d0 <ddbec99f58571301679addbc022256970ca3eac6; version=f266a683a4804dc499efc6c2206ef68efed029d0 <e3b2bfb8ff1810a537b2aa55ba906a6743ed120c
Siemens · SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPversion=V3.1.0 <V3.1.5
Siemens · SIMATIC S7-1500 CPU 1518-4 PN/DP MFPversion=V3.1.0 <V3.1.5

Published CVSS scores

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

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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-908Use of Uninitialized Resource
T1499.004Application 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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