CVE•Published 2025-02-28•Modified 2026-06-30•1 article on news•6 live references•NVD data

CVE-2025-26466Openbsd · Openssh

Vulnerability data via NVD (ingested)

CVSS v3.1

5.9

MEDIUM

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

EPSS percentile

Exploit Prediction Scoring System · top 2% of all CVEs

Weaknesses (CWE)

CWE-770Allocation of Resources Without Limits or Throttling

Description

A flaw was found in the OpenSSH package. For each ping packet the SSH server receives, a pong packet is allocated in a memory buffer and stored in a queue of packages. It is only freed when the server/client key exchange has finished. A malicious client may keep sending such packages, leading to an uncontrolled increase in memory consumption on the server side. Consequently, the server may become unavailable, resulting in a denial of service attack.

Timeline

Published 2025-02-28

Modified 2026-06-30

External references

NVD MITRE Exploit-DB GitHub PoC trickest/cve VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag614,463 hosts

vuln:CVE-2025-26466

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product + version

product:"Openbsd Openssh" version:"9.5"

Version-pinned fingerprint from NVD's first vulnerable CPE.

Shodan · banner/body mention

http.html:"Openssh"

HTTP body or banner mentions "Openssh" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2025-26466