CVE-2026-54886: SSH SFTP server denial of service via extended channel data infinite loop

CSIRTS triage

What

This vulnerability allows denial of service via an infinite loop in extended channel data.

Who is affected

Users of the SSH SFTP server.

Urgency

Remediation is necessary as it could lead to service disruption, although the severity is currently unknown.

Action

Apply the relevant patches for the SSH SFTP server.

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

Details

Source

Microsoft Security Response Center (INTL · vendor-psirt · site)

Severity

unknown

Published

2026-07-02

Exploitation

Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54886

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-2026-548860.33% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 25% of all scored CVEs.

Referenced CVEs

Same CVEs, other sources

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

• medium[NEW] [medium] Erlang/OTP: Multiple vulnerabilitiescert-bund
• mediumCVE-2026-54886: Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in Erlang OTP ssh (ssh_sf…nvd

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