CVE-2026-9547

HIGH

7.4

CVSS v3

Description

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.

CWE-297

How to fix

Remediation Available

curlDebian

Fixed in:8.21.0~rc2-1CVE-2026-9547

curlRed Hat / RHEL

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

curlRocky

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

curl-debuginfoRed Hat / RHEL

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

curl-debuginfoRocky

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

curl-debugsourceRocky

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

curl-debugsourceRed Hat / RHEL

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

curl-minimalRocky

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

curl-minimalRed Hat / RHEL

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

curl-minimal-debuginfoRocky

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

curl-minimal-debuginfoRed Hat / RHEL

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

libcurlRocky

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

libcurlRed Hat / RHEL

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

libcurl-debuginfoRocky

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

libcurl-debuginfoRed Hat / RHEL

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

libcurl-develRed Hat / RHEL

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

libcurl-develRocky

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

libcurl-minimalRed Hat / RHEL

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

libcurl-minimalRocky

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

libcurl-minimal-debuginfoRed Hat / RHEL

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

libcurl-minimal-debuginfoRocky

Fixed in:0:8.12.1-4.el10_2.3RHSA-2026:55450

Fixed in:0:7.76.1-40.el9_8.5RHSA-2026:55439

registry.redhat.io/cert-manager/cert-managerRed Hat / RHEL

Fixed in:operator-rhel9@sha256:6d393c5b9c5a8654da146d816dac94258d5c085d6e1ac9fd15656ae934ca4b38_amd64RHSA-2026:63135

Fixed in:operator-rhel9@sha256:8226f7b24be576cb215a445dc0366e80e4b81b630478390be66c18306116883d_ppc64leRHSA-2026:63135

Fixed in:operator-rhel9@sha256:636dd466ed2874ecc0bc5985dd7c80eb4c4113b4a4989362b616ff7778e19e43_arm64RHSA-2026:63135

Fixed in:operator-rhel9@sha256:99237a55d691dc7906e85773a06ad519f3b9e6206aa74c9014aa1136cabc6c78_s390xRHSA-2026:63135

registry.redhat.io/cert-manager/cert-managerRocky

Fixed in:operator-rhel9@sha256:99237a55d691dc7906e85773a06ad519f3b9e6206aa74c9014aa1136cabc6c78_s390xRHSA-2026:63135

Fixed in:operator-rhel9@sha256:8226f7b24be576cb215a445dc0366e80e4b81b630478390be66c18306116883d_ppc64leRHSA-2026:63135

Fixed in:operator-rhel9@sha256:636dd466ed2874ecc0bc5985dd7c80eb4c4113b4a4989362b616ff7778e19e43_arm64RHSA-2026:63135

Fixed in:operator-rhel9@sha256:6d393c5b9c5a8654da146d816dac94258d5c085d6e1ac9fd15656ae934ca4b38_amd64RHSA-2026:63135

registry.redhat.io/cert-manager/cert-manager-istioRocky

Fixed in:csr-rhel9@sha256:a5b8d2a99391fa45f9090f5cab9ef209ee3ddff67abb3104766241dbaf9e64ad_amd64RHSA-2026:63140

Fixed in:csr-rhel9@sha256:f8bebf6f267ea510545764940d2cc260b9631a7b2d5be4066e1ccc84eb7429ea_ppc64leRHSA-2026:63140

Fixed in:csr-rhel9@sha256:d1d6e21ee1786ffa991bb1780cae3a17a3d9396ddea4e5c4eccb29fd5cac2ca7_arm64RHSA-2026:63140

Fixed in:csr-rhel9@sha256:b0740f7ce0a67df00fbfad64180c4693c7a49af844b3ba4c3a10146c711fc06e_s390xRHSA-2026:63140

registry.redhat.io/cert-manager/cert-manager-istioRed Hat / RHEL

Fixed in:csr-rhel9@sha256:a5b8d2a99391fa45f9090f5cab9ef209ee3ddff67abb3104766241dbaf9e64ad_amd64RHSA-2026:63140

Fixed in:csr-rhel9@sha256:f8bebf6f267ea510545764940d2cc260b9631a7b2d5be4066e1ccc84eb7429ea_ppc64leRHSA-2026:63140

Fixed in:csr-rhel9@sha256:d1d6e21ee1786ffa991bb1780cae3a17a3d9396ddea4e5c4eccb29fd5cac2ca7_arm64RHSA-2026:63140

Fixed in:csr-rhel9@sha256:b0740f7ce0a67df00fbfad64180c4693c7a49af844b3ba4c3a10146c711fc06e_s390xRHSA-2026:63140

registry.redhat.io/cert-manager/jetstack-certRocky

Fixed in:manager-rhel9@sha256:cdb8e7edf0a0438cd8578bedea2e0a4bef66276ac51e20912da5d8ad6d82e266_ppc64leRHSA-2026:63138

Fixed in:manager-rhel9@sha256:afbe54974b9b3bc95455f16baad7e44e629eeb5a4ead75d74b30ac43359937fe_arm64RHSA-2026:63138

Fixed in:manager-rhel9@sha256:97c32b60fc77d27a05fe3ef130d9b69554c793d9df70e0b524d88a5d61254482_s390xRHSA-2026:63138

Fixed in:manager-rhel9@sha256:4d12a56f417d74bba1bd339f05f4b4cfa2a48fd3e0957c51353a6de3f21f4fa8_amd64RHSA-2026:63138

registry.redhat.io/cert-manager/jetstack-certRed Hat / RHEL

Fixed in:manager-rhel9@sha256:cdb8e7edf0a0438cd8578bedea2e0a4bef66276ac51e20912da5d8ad6d82e266_ppc64leRHSA-2026:63138

Fixed in:manager-rhel9@sha256:afbe54974b9b3bc95455f16baad7e44e629eeb5a4ead75d74b30ac43359937fe_arm64RHSA-2026:63138

Fixed in:manager-rhel9@sha256:4d12a56f417d74bba1bd339f05f4b4cfa2a48fd3e0957c51353a6de3f21f4fa8_amd64RHSA-2026:63138

Fixed in:manager-rhel9@sha256:97c32b60fc77d27a05fe3ef130d9b69554c793d9df70e0b524d88a5d61254482_s390xRHSA-2026:63138

registry.redhat.io/cert-manager/jetstack-cert-managerRed Hat / RHEL

Fixed in:acmesolver-rhel9@sha256:f3d617c66947b62a6ff65e68ca48d2ea80d3eb343bcbd245c150fe355d91b534_arm64RHSA-2026:63138

Fixed in:acmesolver-rhel9@sha256:75e764fa7c8af058297efcf6c0b1599cbdb244e15fbe76530429d43b1b168dd2_ppc64leRHSA-2026:63138

Fixed in:acmesolver-rhel9@sha256:71c8d77b5e9ad20eea144b431446f29795a7788a31401ebead4290455cce2b5a_amd64RHSA-2026:63138

Fixed in:acmesolver-rhel9@sha256:03d6509e8064ac056a47ca9ab43df0639236f09806cd551f13a0e808f469c0ee_s390xRHSA-2026:63138

registry.redhat.io/cert-manager/jetstack-cert-managerRocky

Fixed in:acmesolver-rhel9@sha256:71c8d77b5e9ad20eea144b431446f29795a7788a31401ebead4290455cce2b5a_amd64RHSA-2026:63138

Fixed in:acmesolver-rhel9@sha256:f3d617c66947b62a6ff65e68ca48d2ea80d3eb343bcbd245c150fe355d91b534_arm64RHSA-2026:63138

Fixed in:acmesolver-rhel9@sha256:75e764fa7c8af058297efcf6c0b1599cbdb244e15fbe76530429d43b1b168dd2_ppc64leRHSA-2026:63138

Fixed in:acmesolver-rhel9@sha256:03d6509e8064ac056a47ca9ab43df0639236f09806cd551f13a0e808f469c0ee_s390xRHSA-2026:63138

registry.redhat.io/devspaces/codeRocky

Fixed in:rhel9@sha256:5fcb1e5c626c5d3aa85e0ec98062a44803d2815871236a3b7541b95078997c78_s390xRHSA-2026:62260

Fixed in:sshd-rhel9@sha256:5093c89215a4dd74643a2911ce3e3f9e351fda5adf71ee897b7b702840025d47_ppc64leRHSA-2026:62260

Fixed in:rhel9@sha256:37194dd2cd72d6cdb57ca93fd1cfe6e4aa70ec826a3e86032cde0d0738262bd2_ppc64leRHSA-2026:62260

Fixed in:rhel9@sha256:8f84e4d5f4cf71219fbed65092645ded0df00369b42b5487ddef7d0c6cac331b_amd64RHSA-2026:62260

Fixed in:sshd-rhel9@sha256:bce9235e326ab64aabbe7080ca74cbd24d6f9090819d82d9f2f7abb814e3b26f_arm64RHSA-2026:62260

Fixed in:sshd-rhel9@sha256:803f8b179959a2b20c71876814b09bae7e5ee15cc2dc0a7e7e1fded75a52fc8c_amd64RHSA-2026:62260

Fixed in:rhel9@sha256:e576efc0fbec5378a870880a7bce40327a86203f2ff426fb62d8c767f125761a_arm64RHSA-2026:62260

Fixed in:sshd-rhel9@sha256:af4e4fde13a96dd7fd6126bc67927e1873f12fc3263f749527603e60e75e8f5e_s390xRHSA-2026:62260

This vulnerability affects an unusually large number of packages. The highest-confidence fixes are shown above; the full list is longer. Check the referenced advisories for complete coverage.

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityNone

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

Exploit Intelligence

0.33%probability of exploitation in 30 days

26thpercentile

Low risk: more likely to be exploited than 26% of all known CVEs.

References

Patch1

curl.se

Exploit1

hackerone.com

Vendor Advisory1

curl.se

Related Vulnerabilities

Other CWE-297 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2014-3522	Medium	4.0	5.6%	-	Fix
CVE-2018-10936	High	8.1	2.9%	-	Fix
CVE-2024-2466	Medium	6.5	1.3%	-	Fix
CVE-2020-1887	Critical	9.1	1.3%	-	Fix
CVE-2020-14387	High	7.4	1.1%	-	Fix
CVE-2020-15260	Medium	6.8	1.0%	-	Fix

Common questions

How do I fix CVE-2026-9547?

Published advisories record a fix for 77 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2026-9547 being actively exploited?

Not that we know of. CVE-2026-9547 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.33% is the estimated probability that it will be exploited in the next 30 days. That is higher than 26% of all scored CVEs.

How severe is CVE-2026-9547?

CVE-2026-9547 has a CVSS v3 base score of 7.4, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-9547 affect?

Published advisories record a fix for curl (Debian), curl (Red Hat / RHEL), curl (Rocky), curl-debuginfo (Red Hat / RHEL), and 73 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

Embed a live status badge for CVE-2026-9547

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-09-15.