Missing packet length check in OpenSSH sshd and ssh decompression
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · Low · Low
- Fix status
- Partial Red Hat: 1 fixed, 8 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
OpenSSH before 10.6 sshd and ssh do not check whether the maximum packet length is exceeded while decompressing highly compressed data (CWE-409). A remote attacker needs no privileges or user interaction to send such data, which has a low impact on integrity and availability.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In sshd and ssh in OpenSSH before 10.6, there is no check for whether the maximum packet length is exceeded during decompression of highly compressed data.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
OpenSSH 10.6 fixes this flaw. Red Hat fixes it in Red Hat Hardened Images via RHSA-2026:82247, released 2026-10-13. Red Hat lists Red Hat Enterprise Linux 6, 7, 8, 9 and 10 and Red Hat OpenShift Container Platform 4 and 5 as affected with no plan available, and lists Red Hat OpenShift AI (RHOAI) as affected.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA OpenSSH (OpenBSD) Fixed in 10.6
Red Hat 1 advisory
- RHSA-2026:82247 Released 2026-10-13 · Red Hat rating ModerateRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images openssh-10.5p1-1.2.hum1@aarch64, openssh-10.5p1-1.2.hum1@s390x, openssh-10.5p1-1.2.hum1@src +19
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
OpenBSD OpenSSH 10.6
9 records Highest priority Priority LOW 9 LOW
Other records, highest priority first
- TI-2026-69090 Injection via command-line usernames in OpenSSH ssh clientPriority LOW 33
- TI-2026-69088 GSSAPI authentication state persists across attempts in OpenSSH sshdPriority LOW 32
- TI-2026-69087 OpenSSH sshd keeps credentials after failed GSSAPI authenticationPriority LOW 32
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix yet |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat OpenShift AI (RHOAI) | Affected | — |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
| Red Hat Hardened Images | Fixed | RHSA-2026:82247 |
Not affected: 1 product
- Red Hat Hardened Images
Timeline
- 2026-10-07 Threatist record created from CVE-2026-106585
- 2026-10-07 Alias added: GHSA-j4h6-744f-q3hq
- 2026-10-07 Priority changed: MEDIUM → LOW
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-20 Fix available: RHSA-2026:82247 · Red Hat
- 2026-10-20 Fix available: Red Hat Hardened Images · Red Hat
- 2026-10-20 CVSS score added · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
More OpenBSD Openssh vulnerabilities
- TI-2023-19792 The PKCS#11 feature in ssh-agent in OpenSSH before 9.3p2 has an insufficiently… CVSS 3.1CRITICAL 9.8
- TI-2024-05929 Openssh: regresshion - race condition in ssh allows rce/dos CVSS 3.1HIGH 8.1
- TI-2023-10601 OpenSSH server (sshd) 9.1 introduced a double-free vulnerability during… CVSS 3.1MEDIUM 6.5
- TI-2018-11033 OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying… CVSS 3.1MEDIUM 5.9
- TI-2016-08105 Untrusted search path vulnerability in ssh-agent.c in ssh-agent in OpenSSH before 7.4… CVSS 3.1HIGH 7.3
- TI-2023-28040 In ssh in OpenSSH before 9.6, OS command injection might occur if a user name or host… CVSS 3.1MEDIUM 6.5
Sources
- CVE-2026-106585 · CVE Program
- CVE-2026-106585 · NVD
- FIRST EPSS
- GHSA-j4h6-744f-q3hq · GitHub Advisory Database · CC BY 4.0
- CVE-2026-106585 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences