CVE catalog
CVE-2025-26466
OpenSSH vulnerabilities
- Severity
- Medium · CVSS 5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 38.68% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | openssh | sid | 1:10.6p1-1 | fixed |
| Debian | openssh | forky | 1:10.6p1-1 | fixed |
| Debian | openssh | trixie | 1:10.0p1-7+deb13u4 | fixed |
| Debian | openssh | trixie-security | 1:10.0p1-7+deb13u2 | fixed |
| Debian | openssh | bookworm | 1:9.2p1-2+deb12u10 | not affected |
| Debian | openssh | bookworm-security | 1:9.2p1-2+deb12u9 | not affected |
| Ubuntu | openssh | noble | Not reported | not affected |
| Ubuntu | openssh | noble | 1:9.6p1-3ubuntu13.8 | fixed |
| Ubuntu | openssh-client | noble | 1:9.6p1-3ubuntu13.8 | fixed |
| Ubuntu | openssh-server | noble | 1:9.6p1-3ubuntu13.8 | fixed |
| Ubuntu | openssh-sftp-server | noble | 1:9.6p1-3ubuntu13.8 | fixed |
| Ubuntu | openssh-tests | noble | 1:9.6p1-3ubuntu13.8 | fixed |
| Ubuntu | ssh | noble | 1:9.6p1-3ubuntu13.8 | fixed |
| Ubuntu | ssh-askpass-gnome | noble | 1:9.6p1-3ubuntu13.8 | fixed |
| Cpe | openssh | Not reported | Not reported | unknown |
| Cpe | ubuntu_linux | Not reported | Not reported | unknown |
| Cpe | debian_linux | Not reported | Not reported | unknown |
| Alpine | openssh | 3.19 | 9.6_p1-r2 | fixed |
| Alpine | openssh | 3.20 | 9.7_p1-r5 | fixed |
| Alpine | openssh | 3.21 | 9.9_p2-r0 | fixed |
| Alpine | openssh | 3.22 | 9.9_p2-r0 | fixed |
| Alpine | openssh | 3.23 | 9.9_p2-r0 | fixed |
| Alpine | openssh | 3.24 | 9.9_p2-r0 | fixed |
| Ubuntu | openssh | 24.04 | 1:9.3p1-1ubuntu3 | vulnerable |
| Ubuntu | openssh | 24.04 | 1:9.4p1-1ubuntu1 | vulnerable |
| Ubuntu | openssh | 24.04 | 1:9.6p1-3ubuntu1 | vulnerable |
| Ubuntu | openssh | 24.04 | 1:9.6p1-3ubuntu2 | vulnerable |
| Ubuntu | openssh | 24.04 | 1:9.6p1-3ubuntu11 | vulnerable |
| Ubuntu | openssh | 24.04 | 1:9.6p1-3ubuntu12 | vulnerable |
| Ubuntu | openssh | 24.04 | 1:9.6p1-3ubuntu13 | vulnerable |
| Ubuntu | openssh | 24.04 | 1:9.6p1-3ubuntu13.3 | vulnerable |
| Ubuntu | openssh | 24.04 | 1:9.6p1-3ubuntu13.4 | vulnerable |
| Ubuntu | openssh | 24.04 | 1:9.6p1-3ubuntu13.5 | vulnerable |
| Ubuntu | openssh | 24.04 | 1:9.6p1-3ubuntu13.7 | vulnerable |
| Ubuntu | openssh | 24.04 | 1:9.6p1-3ubuntu13.8 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | openssh | source | sid | 1:9.9p2-1 | not yet assigned | Not reported | Not reported |
| Debian | openssh | source | forky | 1:9.9p2-1 | not yet assigned | Not reported | Not reported |
| Debian | openssh | source | trixie | 1:9.9p2-1 | not yet assigned | Not reported | Not reported |
| Debian | openssh | source | bookworm | Not affected | unimportant | Not reported | Not reported |
| Ubuntu | openssh | deb | noble | 1:9.6p1-3ubuntu13.8 | Not reported | Not reported | Not reported |
| Ubuntu | openssh-client | deb | noble | 1:9.6p1-3ubuntu13.8 | Not reported | Not reported | Not reported |
| Ubuntu | openssh-server | deb | noble | 1:9.6p1-3ubuntu13.8 | Not reported | Not reported | Not reported |
| Ubuntu | openssh-sftp-server | deb | noble | 1:9.6p1-3ubuntu13.8 | Not reported | Not reported | Not reported |
| Ubuntu | openssh-tests | deb | noble | 1:9.6p1-3ubuntu13.8 | Not reported | Not reported | Not reported |
| Ubuntu | ssh | deb | noble | 1:9.6p1-3ubuntu13.8 | Not reported | Not reported | Not reported |
| Ubuntu | ssh-askpass-gnome | deb | noble | 1:9.6p1-3ubuntu13.8 | Not reported | Not reported | Not reported |
| Alpine | openssh | apk | 3.19 | 9.6_p1-r2 | Not reported | ALPINE-CVE-2025-26466 | Not reported |
| Alpine | openssh | apk | 3.20 | 9.7_p1-r5 | Not reported | ALPINE-CVE-2025-26466 | Not reported |
| Alpine | openssh | apk | 3.21 | 9.9_p2-r0 | Not reported | ALPINE-CVE-2025-26466 | Not reported |
| Alpine | openssh | apk | 3.22 | 9.9_p2-r0 | Not reported | ALPINE-CVE-2025-26466 | Not reported |
| Alpine | openssh | apk | 3.23 | 9.9_p2-r0 | Not reported | ALPINE-CVE-2025-26466 | Not reported |
| Alpine | openssh | apk | 3.24 | 9.9_p2-r0 | Not reported | ALPINE-CVE-2025-26466 | Not reported |
| Ubuntu | openssh | deb | 24.04 | 1:9.6p1-3ubuntu13.8 | Not reported | UBUNTU-CVE-2025-26466 | Not reported |
OpenFactory catalog packages
Matching against OpenFactory catalog package versions is in progress.
References
- [https://cert-portal.siemens.com/productcert/csaf/ssa-398330.json]
- [https://ftp.suse.com/pub/projects/security/csaf/suse-su-2025_0585-1.json]
- [https://nvd.nist.gov/vuln/detail/CVE-2025-26466]
- [https://osv.dev/vulnerability/ALPINE-CVE-2025-26466]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2025-26466]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2025-26466]
- [https://security-tracker.debian.org/tracker/CVE-2025-26466]
- [https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-26466.json]
- [https://ubuntu.com/security/notices/USN-7270-1]
- [https://wid.cert-bund.de/.well-known/csaf/white/2025/wid-sec-w-2025-0394.json]
[CERT-Bund public advisories] · [CISA cybersecurity advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX] · [Ubuntu Security Notices (USN)]