CVE-2025-26466

mediumpriority · attend · 48EPSS 0.387 · 99 %ileexploit · PoCDEEUNLRUUS

grimoire priorityP1 · Urgent

Exploitable?

Public exploit

5 exploits · PoC

Likely / severe?

38.7% (99th) EPSS

CVSS 5.9 · medium

Is it mine?

68 products

Check your exposure

Who says so?

8 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)siemens_psirt
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)siemens_psirt
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)siemens_psirt
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)siemens_psirt
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)siemens_psirt
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedFirmware < 2025.0.2 installed on AXC F 1152phoenix_contact_psirt
Update to the latest 2025.0.2 Firmware Release. PHOENIX CONTACT recommends to always use an up-to-date version of the PLCnext Engineer.
FixedFirmware < 2025.0.2 installed on AXC F 2152phoenix_contact_psirt
Update to the latest 2025.0.2 Firmware Release. PHOENIX CONTACT recommends to always use an up-to-date version of the PLCnext Engineer.
FixedFirmware < 2025.0.2 installed on AXC F 3152phoenix_contact_psirt
Update to the latest 2025.0.2 Firmware Release. PHOENIX CONTACT recommends to always use an up-to-date version of the PLCnext Engineer.
FixedFirmware < 2025.0.2 installed on BPC 9102Sphoenix_contact_psirt
Update to the latest 2025.0.2 Firmware Release. PHOENIX CONTACT recommends to always use an up-to-date version of the PLCnext Engineer.
FixedFirmware < 2025.0.2 installed on RFC 4072Sphoenix_contact_psirt
Update to the latest 2025.0.2 Firmware Release. PHOENIX CONTACT recommends to always use an up-to-date version of the PLCnext Engineer.
FixedSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)cisa_csaf_ot
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)cisa_csaf_ot
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)cisa_csaf_ot
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)cisa_csaf_ot
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
FixedSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)cisa_csaf_ot
Update to V3.1.5 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/
MitigationSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)cisa_csaf_ot
Only build and run applications from trusted sources.
MitigationSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)cisa_csaf_ot
Only build and run applications from trusted sources.
MitigationSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)cisa_csaf_ot
Only build and run applications from trusted sources.
MitigationSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)cisa_csaf_ot
Only build and run applications from trusted sources.
MitigationSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)cisa_csaf_ot
Only build and run applications from trusted sources.

cvss

Technical severity, 0–10. One row per scoring source.

5.9

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 2.2 · impact 3.6

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · CISA US

v3.15.9mediumAV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · FSTEC (BDU) RU

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · secalert@redhat.com USexploitability 2.2 · impact 3.6

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · Siemens ProductCERT DE

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · Phoenix Contact PSIRT DE

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Hsecondary · CVSS-BT (t0sche)

v3.15.9mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · NCSC-NL NL

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: no · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-400USCWE-400USCWE-400USCWE-400USCWE-770USCWE-770US

exploits (5)

Public proof-of-concept and weaponised exploit code.

K0n9-log/cve-2025-26466-canvasK0n9-log/cve-2025-26466-canvasPoC · poc_in_github
acidboonrs/cve-2025-26466-openssh-pocCVE-2025-26466 OpenSSH SSH2_MSG_PING DoS PoCPoC · poc_in_github
mrowkoob/CVE-2025-26466-msfCVE-2025-26466 - SSH Ping DoS Ruby module for Metasploit FrameworkPoC · poc_in_github
rxerium/CVE-2025-26466 The OpenSSH client and server are vulnerable to a pre-authentication DoS attack between versions 9.5p1 to 9.9p1 (inclusive) that causes memory and CPU consumptionPoC · poc_in_github
tpirate/CVE-2025-26466poc for CVE-2025-26466PoC · poc_in_github

affected products (68)

Products and version ranges known to be affected.

Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
Dell Dell Secure Connect Gateway <5.30.0.14< 5.30.0.14cert_bundDE
Dell Secure Connect Gateway< 5.30.0.14cert_bundDE
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)all versionscisa_csaf_otUS
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)all versionscisa_csaf_otUS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)all versionscisa_csaf_otUS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)all versionscisa_csaf_otUS
SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)all versionscisa_csaf_otUS
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)≤ vers:intdot/>=3.1.0|<3.1.5cisa_csaf_otUS
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)≤ vers:intdot/>=3.1.0|<3.1.5cisa_csaf_otUS
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)≤ vers:intdot/>=3.1.0|<3.1.5cisa_csaf_otUS
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)≤ vers:intdot/>=3.1.0|<3.1.5cisa_csaf_otUS
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)≤ vers:intdot/>=3.1.0|<3.1.5cisa_csaf_otUS
Canonical Ltd. Ubuntu≤ 24.04 LTSfstec_bduRU
Canonical Ltd. Ubuntu≤ 24.10fstec_bduRU
Novell Inc. OpenSUSE Leap≤ 15.6fstec_bduRU
Novell Inc. SUSE Linux Enterprise High Performance Computing≤ 15 SP6fstec_bduRU
Novell Inc. SUSE Linux Enterprise Module for Basesystem≤ 15 SP6fstec_bduRU

showing 20 of 68

advisories (10)

Vendor and ecosystem advisories describing this.

NCSC-2025-0151Kwetsbaarheden verholpen in Apple macOSNL2025-05-13csaf · ncsc_nlNL
Apple heeft kwetsbaarheden verholpen in macOS (Specifiek voor Ventura 13.7.6, Sequoia 15.5 en Sonoma 14.7.6).
NCSC-2025-0166Kwetsbaarheden verholpen in Fortinet productenNL2025-05-14csaf · ncsc_nlNL
Fortinet heeft kwetsbaarheden verholpen in FortiManager, FortiManager Cloud, FortiAnalyzer, FortiOS, FortiProxy, FortiPAM, FortiSRA, FortiSwitchManager en FortiWeb.
SSA-398330SSA-398330: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.52023-12-12csaf · siemens_psirtDE
Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version >= V3.1.0 and < V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). These GNU/Linux vulnerabilities have been externally identified. Siemens has released new versions for the affected products and recommends to update to the latest versions. SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP >= V3.1.0 and < V3.1.5 are no longer maintained and there won't be any update to the CVE list anymore. Please update to the latest version. Note: This SSA advises vulnerabilities for firmware version V3.1 only; for versions < V3.1 refer to Siemens Security Bulletin SSB-439005 (https://cert-portal.siemens.com/productcert/html/ssb-439005.html).
VDE-2025-053Phoenix Contact: Multiple Vulnerabilities in PLCnext Firmware2025-07-08csaf · phoenix_contact_psirtDE
Multiple Linux component vulnerabilities fixed in latest PLCnext Firmware release 2025.0.2
WID-SEC-W-2025-0394OpenSSH: Mehrere SchwachstellenDeutsch2025-02-17csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in OpenSSH ausnutzen, um kryptografische Sicherheitsvorkehrungen zu umgehen und um einen Denial of Service Zustand herbeizuführen.
WID-SEC-W-2025-1007Apple macOS: Mehrere SchwachstellenDeutsch2025-05-12csaf · cert_bundDE
Ein entfernter anonymer Angreifer kann mehrere Schwachstellen in Apple macOS ausnutzen, um erhöhte Privilegien zu erlangen, vertrauliche Informationen offenzulegen, beliebigen Code auszuführen, Daten zu manipulieren, Sicherheitsmaßnahmen zu umgehen oder einen Denial-of-Service-Zustand auszulösen.
WID-SEC-W-2025-1439Dell Secure Connect Gateway: Mehrere Schwachstellen ermöglichen nicht spezifizierten AngriffDeutsch2025-06-30csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Dell Secure Connect Gateway ausnutzen, um einen nicht näher spezifizierten Angriff durchzuführen.
WID-SEC-W-2025-1519Juniper JUNOS: Mehrere Schwachstellen ermöglichen PrivilegieneskalationDeutsch2025-07-09csaf · cert_bundDE
Ein entfernter Angreifer kann mehrere Schwachstellen in Juniper JUNOS, Juniper MX Series, Juniper SRX Series und Juniper Security Director ausnutzen, um Daten zu manipulieren oder offenzulegen, Sicherheitsmaßnahmen zu umgehen, Code auszuführen, einen Denial of Service zu verursachen oder seine Privilegien zu erweitern.
WID-SEC-W-2025-2633Aruba AOS-CX: Mehrere SchwachstellenDeutsch2025-11-18csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Aruba AOS-CX ausnutzen, um seine Privilegien zu erhöhen, um einen Denial of Service Angriff durchzuführen, um beliebigen Programmcode auszuführen, um Informationen offenzulegen, und um Dateien zu manipulieren.
ICSA-23-348-10Siemens SIMATIC S7-15002023-12-12icsa · cisa_csaf_otUS
Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version >= V3.1.0 and < V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). These GNU/Linux vulnerabilities have been externally identified. Siemens has released new versions for the affected products and recommends to update to the latest versions. Note: This SSA advises vulnerabilities for firmware version V3.1 only; for versions < V3.1 refer to Siemens Security Bulletin SSB-439005 ( https://cert-portal.siemens.com/productcert/html/ssb-439005.html).

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund cisa_csaf_ot ncsc_nl siemens_psirt phoenix_contact_psirt NVD CVE.org MITRE

published 2025-02-28modified 2026-10-21

references (29)

External citations — patches, advisories, analysis.

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