CVE Tools
Track your stack

CVE-2025-26465

Openssh: machine-in-the-middle attack if verifyhostkeydns is enabled

Public exploit available. Not confirmed exploited in the wild yet. A vendor fix is available.

CVSS 3.16.8MediumEPSS percentile94th7.7% chance in 30 daysCISA KEVNot listedNo confirmed exploitation
Public exploit: 1 sourceFixVendor fixNo build named by the sources

Published Updated Sources: CVE.org, NVD, BDU, CSAF

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

A vulnerability was found in OpenSSH when the VerifyHostKeyDNS option is enabled. A machine-in-the-middle attack can be performed by a malicious machine impersonating a legit server. This issue occurs due to how OpenSSH mishandles error codes in specific conditions when verifying the host key. For an attack to be considered successful, the attacker needs to manage to exhaust the client's memory resource first, turning the attack complexity high.

In plain language

No plain-language summary for this CVE yet.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS94th
Public exploit
CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

1 source with a proof of concept or module.

Exploit links, PoCs and Metasploit modules after sign-in
EPSS

7.7% chance of exploitation activity in the next 30 days, which ranks it in the 94th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

A public exploit existed 67 days before the patch.

  1. Patch availableworkaround available, record updated
  2. Patch availableworkaround available, record updated
  3. OpenVAS check added
  4. EPSS band changehigh → low
  5. Patch availableworkaround available, record updated
  6. Public exploit / PoCsource: github-poc

Affected products

And 19 more affected products. See all after sign-in

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N

Scored 6.8 by NVD.

How it is reached

  • Attack Vector NetworkExploitable remotely over the network without any special conditions
  • Attack Complexity HighRequires specific conditions like a race condition or non-default configuration
  • Privileges Required NoneNo authentication required — anyone can exploit this
  • User Interaction RequiredA user must click a link, open a file, or perform some action

Scope

  • Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

  • Confidentiality HighTotal information disclosure — all data in the component is compromised
  • Integrity HighTotal loss of integrity — attacker can modify any data in the component
  • Availability NoneNo availability impact

Weaknesses

Sources

References in the record

And 86 more references. See all after sign-in

Watch the software you run.

My Stack ranks new CVEs for your products by real-world exploitation, so the next serious one reaches you without reading every advisory.

We'll flag the next CVE, public exploit or patch for OpenSUSE Tumbleweed, not every advisory. This one: public exploit.

We use analytics cookies to see which pages and articles actually help people. Decline and none of them run — the site works the same. What we store