Use after free in OpenBSD OpenSSH
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- Partial Red Hat: 9 fixed, 4 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In ssh in OpenSSH before 10.5, a use-after-free for realloc data can occur if a certain pair of remote-forwarding operations are concurrent.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- 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
- Fix · CNA OpenSSH (OpenBSD) Fixed in 10.5
Red Hat 6 advisories
- RHSA-2026:76748 Released 2026-10-06 · Red Hat rating Importantopenssh security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) openssh-askpass-9.9p1-7.el10_0.5, openssh-keysign-9.9p1-7.el10_0.5
- Red Hat Enterprise Linux BaseOS EUS (v. 10.0) openssh-9.9p1-7.el10_0.5, openssh-clients-9.9p1-7.el10_0.5, openssh-keycat-9.9p1-7.el10_0.5 +1
- RHSA-2026:71603 Released 2026-09-24 · Red Hat rating ImportantRed Hat Update Infrastructure 5.3 security update
- Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-rhel9, registry.redhat.io/rhui5/cds-rhel9, registry.redhat.io/rhui5/haproxy-rhel9 +2
- RHSA-2026:70719 Released 2026-09-23 · Red Hat rating ModerateRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images openssh-10.5p1-1.hum1@aarch64, openssh-10.5p1-1.hum1@src, openssh-10.5p1-1.hum1@x86_64 +12
Show 3 more Red Hat advisories
- RHSA-2026:69130 Released 2026-09-21 · Red Hat rating Importantopenssh security update
- Red Hat Enterprise Linux AppStream (v. 9) openssh-askpass-9.9p1-11.el9_8, pam_ssh_agent_auth-0.10.4-8.11.el9_8
- Red Hat Enterprise Linux BaseOS (v. 9) openssh-9.9p1-11.el9_8, openssh-clients-9.9p1-11.el9_8, openssh-keycat-9.9p1-11.el9_8 +1
- RHSA-2026:69266 Released 2026-09-21 · Red Hat rating Importantopenssh security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 8) openssh-askpass-8.0p1-33.el8_10
- Red Hat Enterprise Linux BaseOS (v. 8) openssh-8.0p1-33.el8_10, openssh-cavs-8.0p1-33.el8_10, openssh-clients-8.0p1-33.el8_10 +4
- RHSA-2026:69129 Released 2026-09-21 · Red Hat rating Importantopenssh security update
- Red Hat Enterprise Linux AppStream (v. 10) openssh-askpass-9.9p1-27.el10_2, openssh-keysign-9.9p1-27.el10_2
- Red Hat Enterprise Linux BaseOS (v. 10) openssh-9.9p1-27.el10_2, openssh-clients-9.9p1-27.el10_2, openssh-keycat-9.9p1-27.el10_2 +1
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
OpenBSD OpenSSH 10.5
3 records Highest priority Priority LOW 3 LOW
Other records, highest priority first
- TI-2026-51406 In ssh-agent in OpenSSH before 10.5, some operations can occur remotely but were intended…Priority LOW 16
- TI-2026-51408 In sshd in OpenSSH before 10.5, the restrict keyword (in authorized_keys) was supposed to…Priority LOW 12
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:69129 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:69266 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:69130 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:69129 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2026:69266 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:69130 |
| Red Hat Enterprise Linux BaseOS EUS (v. 10.0) | Fixed | RHSA-2026:76748 |
| Red Hat Hardened Images | Fixed | RHSA-2026:70719 |
| Red Hat Update Infrastructure 5 | Fixed | RHSA-2026:71603 |
Not affected: 3 products
- Red Hat Enterprise Linux AppStream EUS (v. 10.0)
- Red Hat Enterprise Linux BaseOS EUS (v. 10.0)
- Red Hat Update Infrastructure 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-73282
- 2026-10-03 Alias added: GHSA-jwc3-6qvm-4r66
- 2026-10-06 Fix available: Red Hat Enterprise Linux BaseOS EUS (v. 10.0) · Red Hat
- 2026-10-07 Fix available: RHSA-2026:76748 · 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-2026-73282 · CVE Program
- CVE-2026-73282 · NVD
- FIRST EPSS
- GHSA-jwc3-6qvm-4r66 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-73282 · 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