[UPDATE] [medium] OpenSSH: Multiple vulnerabilities

mediumCVE-2026-55653 CVE-2026-55654 CVE-2026-55655

An attacker can exploit multiple vulnerabilities in OpenSSH to conduct a denial of service attack, bypass security measures, manipulate data, or disclose confidential information.

CSIRTS triage

vendor: OpenSSH product: OpenSSH Denial of service Authentication bypass Information disclosureOther

What: Multiple vulnerabilities can be exploited to conduct a denial of service attack, bypass security measures, manipulate data, or disclose confidential information.
Who is affected: Deployments of OpenSSH are affected.
Urgency: Remediation is medium urgency as exploitation is possible but not currently active.
Action: Update to the latest version of OpenSSH.

AI-assisted analysis generated from the source advisory — verify against the original.

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Details

Source: CERT-Bund (BSI) Security Advisories (DE · national-cert · site)
Severity: medium
Published: 2026-08-17
Exploitation: Not in CISA KEV at last sync
Language: Machine-translated to English — verify against the original

Original advisory: https://wid.cert-bund.de/portal/wid/securityadvisory?name=WID-SEC-2026-2039

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-556530.29% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 22% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-556540.43% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 36% of all EPSS-scored CVEs.
Low exploitation riskCVE-2026-556550.09% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 1% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-55653	coverage & exploitation status	NVD · CVE.org
CVE-2026-55654	coverage & exploitation status	NVD · CVE.org
CVE-2026-55655	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

Recent advisories for OpenSSH

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

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