CVE-2026-73489Public exploitNetwork attack vector

Authenticated session-task crash via unchecked terminal-mode count

Published Aug 13, 2026 · Updated Aug 13, 2026

Denial of service in Eugeny russh before 0.62.4 allows remote authenticated users to crash an SSH server session via a pty-req. The pty-req parser in russh/src/server/encrypted.rs increments its terminal-mode counter beyond a fixed 130-entry array, then slices the array to that unchecked count and panics. Any authenticated client able to open a session channel can terminate that session task with 131 valid mode records; no memory corruption or confidentiality or integrity impact is demonstrated.

CVSS severity4.3
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Eugeny russh before 0.62.4 allows remote authenticated users to crash an SSH server session via a pty-req. The pty-req parser in russh/src/server/encrypted.rs increments its terminal-mode counter beyond a fixed 130-entry array, then slices the array to that unchecked count and panics. Any authenticated client able to open a session channel can terminate that session task with 131 valid mode records; no memory corruption or confidentiality or integrity impact is demonstrated.

The record

CVE
CVE-2026-73489
Published
Aug 13, 2026
Updated
Aug 13, 2026
Vendor
Russh Project
Product
russh
Classifications
T1499.004
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 13, 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=< 0.62.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Russh Project · russhversion=< 0.62.4

Published CVSS scores

4.3GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

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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