SSH improper host validation
Priority HIGH 68CWE-297Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · None
- Fix status
- Partial Red Hat: 18 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
Summary
When a libcurl-based application performs transfers via `SCP://` or `SFTP://` and utilizes the `CURLOPT_SSH_KEYFUNCTION` callback, it may silently accept an untrusted server. This vulnerability occurs when a server presents a host key type that does not match the specific key type already recorded for that host in the `known_hosts` file. Instead of rejecting the mismatch, the callback mechanism fails to properly enforce the restriction, allowing the connection to succeed without warning and risking a potential man-in-the-middle attack.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00361 30th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial curl (curl): 8.14.2, 8.16.1, 8.20.1Red Hat: 31 advisoriesRed Hat: 18 fixed, 1 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| curl | curl | 7.69.0 to before 8.14.2; 8.15.0 to before 8.16.1; 8.17.0 to before 8.20.1 | 8.14.2, 8.16.1, 8.20.1 | Patch available | CNA |
| curl | curl | 8.20.0; 8.19.0; 8.18.0; 8.17.0; 8.16.0; 8.15.0; 8.14.1; 8.14.0; 8.13.0; 8.12.1; 8.12.0; 8.11.1; 8.11.0; 8.10.1; 8.10.0; 8.9.1; 8.9.0; 8.8.0; 8.7.1; 8.7.0; 8.6.0; 8.5.0; 8.4.0; 8.3.0; 8.2.1; 8.2.0; 8.1.2; 8.1.1; 8.1.0; 8.0.1; 8.0.0; 7.88.1; 7.88.0; 7.87.0; 7.86.0; 7.85.0; 7.84.0; 7.83.1; 7.83.0; 7.82.0; 7.81.0; 7.80.0; 7.79.1; 7.79.0; 7.78.0; 7.77.0; 7.76.1; 7.76.0; 7.75.0; 7.74.0; 7.73.0; 7.72.0; 7.71.1; 7.71.0; 7.70.0; 7.69.1; 7.69.0 | — | No fix listed | CNA |
- curl Vendorcurl Affected 7.69.0 to before 8.14.2; 8.15.0 to before 8.16.1; 8.17.0 to before 8.20.1 Fixed in 8.14.2, 8.16.1, 8.20.1 Patch available CNA
- curl Vendorcurl Affected 8.20.0; 8.19.0; 8.18.0; 8.17.0; 8.16.0; 8.15.0; 8.14.1; 8.14.0; 8.13.0; 8.12.1; 8.12.0; 8.11.1; 8.11.0; 8.10.1; 8.10.0; 8.9.1; 8.9.0; 8.8.0; 8.7.1; 8.7.0; 8.6.0; 8.5.0; 8.4.0; 8.3.0; 8.2.1; 8.2.0; 8.1.2; 8.1.1; 8.1.0; 8.0.1; 8.0.0; 7.88.1; 7.88.0; 7.87.0; 7.86.0; 7.85.0; 7.84.0; 7.83.1; 7.83.0; 7.82.0; 7.81.0; 7.80.0; 7.79.1; 7.79.0; 7.78.0; 7.77.0; 7.76.1; 7.76.0; 7.75.0; 7.74.0; 7.73.0; 7.72.0; 7.71.1; 7.71.0; 7.70.0; 7.69.1; 7.69.0 Fixed in — No fix listed CNA
Remediation
- Fix · CNA curl (curl) Fixed in 8.14.2, 8.16.1, 8.20.1
Red Hat 31 advisories
- RHSA-2026:93454 Released 2026-11-02 · Red Hat rating Importantcurl security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) libcurl-devel-7.76.1-31.el9_6.4
- Red Hat Enterprise Linux BaseOS EUS (v.9.6) curl-7.76.1-31.el9_6.4, curl-minimal-7.76.1-31.el9_6.4, libcurl-7.76.1-31.el9_6.4 +1
- RHSA-2026:82888 Released 2026-10-14 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.17.2
- Cert Manager support for Red Hat OpenShift release 1.17 registry.redhat.io/cert-manager/cert-manager-operator-bundle
- RHSA-2026:82857 Released 2026-10-14 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.18.2
- Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-operator-bundle
Show 28 more Red Hat advisories
- RHSA-2026:82372 Released 2026-10-13 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.18.2
- Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
- RHSA-2026:82354 Released 2026-10-13 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.18.2
- Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/cert-manager-istio-csr-rhel9
- RHSA-2026:82347 Released 2026-10-13 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.18.2
- Cert Manager support for Red Hat OpenShift release 1.18 registry.redhat.io/cert-manager/jetstack-cert-manager-acmesolver-rhel9, registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
- RHSA-2026:82336 Released 2026-10-13 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.17.1
- Cert Manager support for Red Hat OpenShift release 1.17 registry.redhat.io/cert-manager/cert-manager-istio-csr-rhel9
- RHSA-2026:82322 Released 2026-10-13 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.17.2
- Cert Manager support for Red Hat OpenShift release 1.17 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
- RHSA-2026:82304 Released 2026-10-13 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.17.2
- Cert Manager support for Red Hat OpenShift release 1.17 registry.redhat.io/cert-manager/jetstack-cert-manager-acmesolver-rhel9, registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
- RHSA-2026:72506 Released 2026-09-28 · Red Hat rating Importantcurl security update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) libcurl-devel-8.12.1-1.el10_0.10
- Red Hat Enterprise Linux BaseOS EUS (v. 10.0) curl-8.12.1-1.el10_0.10, libcurl-8.12.1-1.el10_0.10, libcurl-minimal-8.12.1-1.el10_0.10
- RHSA-2026:72502 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/cert-manager-trust-manager-rhel9
- RHSA-2026:72476 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
- RHSA-2026:72475 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/cert-manager-istio-csr-rhel9
- RHSA-2026:72470 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/jetstack-cert-manager-acmesolver-rhel9, registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
- RHSA-2026:72399 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
- RHSA-2026:72395 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/cert-manager-istio-csr-rhel9
- RHSA-2026:72394 Released 2026-09-28 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.20.1
- Cert Manager support for Red Hat OpenShift release 1.20 registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
- RHSA-2026:66357 Released 2026-09-15 · Red Hat rating ImportantOpenShift Container Platform 4.22.14 bug fix and security update
- Red Hat OpenShift Container Platform 4.22 rhcos-aarch64-4.22.9.8.202609081748-0, rhcos-ppc64le-4.22.9.8.202609081748-0, rhcos-s390x-4.22.9.8.202609081748-0 +1
- RHSA-2026:66018 Released 2026-09-09 · 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-2026:63140 Released 2026-09-03 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.19.2
- Cert Manager support for Red Hat OpenShift release 1.19 registry.redhat.io/cert-manager/cert-manager-istio-csr-rhel9
- RHSA-2026:63138 Released 2026-09-03 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.19.2
- Cert Manager support for Red Hat OpenShift release 1.19 registry.redhat.io/cert-manager/jetstack-cert-manager-acmesolver-rhel9, registry.redhat.io/cert-manager/jetstack-cert-manager-rhel9
- RHSA-2026:63135 Released 2026-09-03 · Red Hat rating Importantcert-manager Operator for Red Hat OpenShift 1.19.2
- Cert Manager support for Red Hat OpenShift release 1.19 registry.redhat.io/cert-manager/cert-manager-operator-rhel9
- RHSA-2026:60440 Released 2026-09-01 · Red Hat rating ImportantOpenShift Container Platform 4.22.12 bug fix and security update
- Red Hat OpenShift Container Platform 4.22 rhcos-aarch64-4.22.9.8.202608251819-0, rhcos-ppc64le-4.22.9.8.202608251819-0, rhcos-s390x-4.22.9.8.202608251819-0 +1
- RHSA-2026:62260 Released 2026-09-01 · Red Hat rating ImportantRed Hat OpenShift Dev Spaces 3.30.0 Release.
- Red Hat OpenShift Dev Spaces 3.30 registry.redhat.io/devspaces/code-rhel9, registry.redhat.io/devspaces/configbump-rhel9, registry.redhat.io/devspaces/dashboard-rhel9 +7
- RHSA-2026:61783 Released 2026-08-31 · Red Hat rating ImportantA Subscription Management tool for finding and reporting Red Hat product usage
- Red Hat Discovery 2 registry.redhat.io/discovery/discovery-server-rhel9, registry.redhat.io/discovery/discovery-ui-rhel9
- RHSA-2026:58981 Released 2026-08-24 · Red Hat rating CriticalRed Hat Update Infrastructure 5.3 Technology Preview security update
- Red Hat Update Infrastructure 5 registry.redhat.io/rhui5/cds-kubernetes-tp-rhel9, registry.redhat.io/rhui5/installer-tp-rhel9, registry.redhat.io/rhui5/rhua-tp-rhel9
- RHSA-2026:56869 Released 2026-08-19 · Red Hat rating ImportantRed Hat JBoss Core Services Apache HTTP Server 2.4.62 SP5 security update
- Red Hat JBoss Core Services 2.4.62.SP5
- RHSA-2026:55439 Released 2026-08-17 · Red Hat rating Importantcurl security update
- Red Hat Enterprise Linux AppStream (v. 9) libcurl-devel-7.76.1-40.el9_8.5
- Red Hat Enterprise Linux BaseOS (v. 9) curl-7.76.1-40.el9_8.5, curl-minimal-7.76.1-40.el9_8.5, libcurl-7.76.1-40.el9_8.5 +1
- RHSA-2026:55450 Released 2026-08-17 · Red Hat rating Importantcurl security update
- Red Hat Enterprise Linux AppStream (v. 10) libcurl-devel-8.12.1-4.el10_2.3
- Red Hat Enterprise Linux BaseOS (v. 10) curl-8.12.1-4.el10_2.3, libcurl-8.12.1-4.el10_2.3, libcurl-minimal-8.12.1-4.el10_2.3
- RHSA-2026:34975 Released 2026-07-02 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images cargo-1.96.1-1.hum1@aarch64, cargo-1.96.1-1.hum1@x86_64, clippy-1.96.1-1.hum1@aarch64 +36
- RHSA-2026:29017 Released 2026-06-24 · Red Hat rating ImportantRed Hat Hardened Images RPMs bug fix and enhancement update
- Red Hat Hardened Images curl-8.21.0-0.1.hum1@aarch64, curl-8.21.0-0.1.hum1@src, curl-8.21.0-0.1.hum1@x86_64 +6
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
curl 8.14.2, 8.16.1, 8.20.1
13 records Highest priority Priority HIGH 12 HIGH, 1 MEDIUM
Other records, highest priority first
- TI-2026-10231 cross-origin Digest auth state leakPriority HIGH 82
- TI-2026-09063 HTTP/2 stream-dependency tree UAFPriority HIGH 82
- TI-2026-07976 stale proxy password leakPriority HIGH 82
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet |
| Cert Manager support for Red Hat OpenShift release 1.17 | Fixed | RHSA-2026:82304, RHSA-2026:82322, RHSA-2026:82336, RHSA-2026:82888 |
| Cert Manager support for Red Hat OpenShift release 1.18 | Fixed | RHSA-2026:82347, RHSA-2026:82354, RHSA-2026:82372, RHSA-2026:82857 |
| Cert Manager support for Red Hat OpenShift release 1.19 | Fixed | RHSA-2026:63135, RHSA-2026:63138, RHSA-2026:63140 |
| Cert Manager support for Red Hat OpenShift release 1.20 | Fixed | RHSA-2026:72394, RHSA-2026:72395, RHSA-2026:72399, RHSA-2026:72470, RHSA-2026:72475, RHSA-2026:72476, RHSA-2026:72502 |
| Red Hat Discovery 2 | Fixed | RHSA-2026:61783 |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:55450 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:55439 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:72506 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:93454 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:55450 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:55439 |
| Red Hat Enterprise Linux BaseOS EUS (v. 10.0) | Fixed | RHSA-2026:72506 |
| Red Hat Enterprise Linux BaseOS EUS (v.9.6) | Fixed | RHSA-2026:93454 |
| Red Hat Hardened Images | Fixed | RHSA-2026:29017, RHSA-2026:34975 |
| Red Hat JBoss Core Services 2.4.62.SP5 | Fixed | RHSA-2026:56869 |
| Red Hat OpenShift Container Platform 4.22 | Fixed | RHSA-2026:60440, RHSA-2026:66357 |
| Red Hat OpenShift Dev Spaces 3.30 | Fixed | RHSA-2026:62260 |
| Red Hat Update Infrastructure 5 | Fixed | RHSA-2026:58981, RHSA-2026:66018 |
Not affected: 9 products
- Cert Manager support for Red Hat OpenShift release 1.20
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat OpenShift AI (RHOAI)
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Dev Spaces 3.30
- Red Hat Trusted Profile Analyzer
- Red Hat Update Infrastructure 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-9547
- 2026-10-03 Alias added: GHSA-xq9p-gxg6-f7q6
- 2026-10-09 Fix available: RHSA-2026:56869 · Red Hat
- 2026-10-09 Fix available: Red Hat JBoss Core Services 2.4.62.SP5 · Red Hat
- 2026-10-14 Fix available: RHSA-2026:82304 · Red Hat
- 2026-10-14 Fix available: RHSA-2026:82322 · Red Hat
- 2026-10-14 Fix available: RHSA-2026:82336 · Red Hat
- 2026-10-14 Fix available: RHSA-2026:82372 · Red Hat
- 2026-10-14 Fix available: RHSA-2026:82354 · Red Hat
- 2026-10-14 Fix available: RHSA-2026:82347 · Red Hat
- 2026-10-15 Fix available: RHSA-2026:82857 · Red Hat
- 2026-10-15 Fix available: RHSA-2026:82888 · Red Hat
- 2026-10-16 Fix available: Cert Manager support for Red Hat OpenShift release 1.17, Cert Manager support for Red Hat OpenShift release 1.18 · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
- 2026-11-02 Fix available: RHSA-2026:93454 · Red Hat
- 2026-11-02 Fix available: Red Hat Enterprise Linux AppStream EUS (v.9.6), Red Hat Enterprise Linux BaseOS EUS (v.9.6) · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
More curl vulnerabilities
- TI-2023-19922 Out-of-bounds write in curl CVSS 3.1CRITICAL 9.8
- TI-2026-16162 Negotiate ambient user conn reuse CVSS 3.1CRITICAL 9.8
- TI-2026-10231 cross-origin Digest auth state leak CVSS 3.1CRITICAL 9.8
- TI-2026-09063 HTTP/2 stream-dependency tree UAF CVSS 3.1CRITICAL 9.8
- TI-2026-07976 stale proxy password leak CVSS 3.1CRITICAL 9.8
- TI-2026-07845 SASL double-free CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-9547 · CVE Program
- CVE-2026-9547 · NVD
- FIRST EPSS
- GHSA-xq9p-gxg6-f7q6 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-9547 · Red Hat security data · CC BY 4.0
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