CVE-2026-48108Public exploitNetwork attack vector

Pre-authentication resource exhaustion via unbounded client pre-banners

Published Jun 10, 2026 · Updated Jun 10, 2026

Improper input validation in Eugeny russh 0.34.0-beta.1 through 0.60.x allows remote attackers to hold SSH setup resources. The server path reuses the client-side read_ssh_id behavior, discards unlimited non-SSH pre-banner lines, and waits for a later identification string instead of rejecting the first invalid client line. Unauthenticated network access to a russh-based SSH server is sufficient; repeated malformed lines can prolong cleartext connection setup until an application timeout or external limit intervenes.

CVSS severity5.3
Medium
EPSS probability0.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Eugeny russh 0.34.0-beta.1 through 0.60.x allows remote attackers to hold SSH setup resources. The server path reuses the client-side read_ssh_id behavior, discards unlimited non-SSH pre-banner lines, and waits for a later identification string instead of rejecting the first invalid client line. Unauthenticated network access to a russh-based SSH server is sufficient; repeated malformed lines can prolong cleartext connection setup until an application timeout or external limit intervenes.

The record

CVE
CVE-2026-48108
Published
Jun 10, 2026
Updated
Jun 10, 2026
Vendor
Russh Project
Product
russh
Classifications
CWE-20, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 10, 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=>= 0.34.0-beta.1, < 0.61.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Russh Project · russhversion=>= 0.34.0-beta.1, < 0.61.0

Published CVSS scores

5.3GitHubCVSS:3.1/AV:N/AC:L/PR:N/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

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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