CVE-2026-9547

curl: When a libcurl-based application performs transfers via `SCP://` or `SFTP://` and utilizes the `CURLOPT_SSH_KEYFUNCTI...

CVE-2026-9547 is fixed in 16 products on 1 platform, first by curl 8.18.0-1ubuntu2.2, released June 26, 2026. It is not reported as exploited. Patch Radar priority: High.

High
CVSS
8.1
high
Exploitation
None reported
No vendor assessment
CISA KEV
Not listed
Not in the Known Exploited Vulnerabilities catalog
EPSS
0.0036
30th percentile

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.

Where it's fixed

ProductFixed inFixReleased
Linux
curl · Debian 14 8.21.0~rc2-1 DEBIAN-CVE-2026-9547 Jul 24, 2026
curl · RHEL 10 8.12.1-1.el10_0.10 RHSA-2026:72506 Jul 3, 2026
curl · RHEL 9 0:7.76.1-40.el9_8.5 RHSA-2026:55439 Aug 19, 2026
curl · Ubuntu 22.04.1 LTS (jammy) 7.81.0-1ubuntu1.25 curl 7.81.0-1ubuntu1.25 Jul 3, 2026
curl · Ubuntu 24.04.5 LTS (noble) 8.5.0-2ubuntu10.10 curl 8.5.0-2ubuntu10.10 Jul 3, 2026
curl · Ubuntu 25.10 (questing) 8.14.1-2ubuntu1.4 curl 8.14.1-2ubuntu1.4 Jul 3, 2026
curl · Ubuntu 26.04.1 LTS (resolute) 8.18.0-1ubuntu2.2 curl 8.18.0-1ubuntu2.2 Jun 26, 2026
curl · almalinux 9 7.76.1-40.el9_8.5 ALSA-2026:55439 Aug 17, 2026
curl · amzn 2023 8.21.0-5.amzn2023.0.1 ALAS2023-2026-2132 Sep 14, 2026
curl · ol 10 0:8.12.1-4.el10_2.4 ELSA-2026-55450 Aug 17, 2026
curl · ol 9 0:7.76.1-40.el9_8.5 ELSA-2026-55439 Aug 17, 2026
curl · opensuse-leap 16.0 8.14.1-160000.8.1 OPENSUSE-SU-2026:21272-1 Jul 8, 2026
curl · rocky 9 0:7.76.1-40.el9_8.5 RLSA-2026:55439 Aug 17, 2026
curl · sles 15.6 8.14.1-150600.4.46.1 SUSE-SU-2026:2926-1 Jul 13, 2026
curl · sles 15.7 8.14.1-150700.7.20.1 SUSE-SU-2026:2925-1 Jul 13, 2026
curl · sles 16.0 8.14.1-160000.8.1 SUSE-SU-2026:22582-1 Jul 8, 2026
curl-debuginfo · amzn 2023 8.21.0-5.amzn2023.0.1 ALAS2023-2026-2132 Sep 14, 2026
curl-debugsource · amzn 2023 8.21.0-5.amzn2023.0.1 ALAS2023-2026-2132 Sep 14, 2026
curl-mini · sles 16.0 8.14.1-160000.8.1 SUSE-SU-2026:22582-1 Jul 8, 2026
curl-minimal · RHEL 9 0:7.76.1-40.el9_8.5 RHSA-2026:55439 Aug 19, 2026
curl-minimal · almalinux 9 7.76.1-40.el9_8.5 ALSA-2026:55439 Aug 17, 2026
curl-minimal · amzn 2023 8.21.0-5.amzn2023.0.1 ALAS2023-2026-2132 Sep 14, 2026
curl-minimal · ol 9 0:7.76.1-40.el9_8.5 ELSA-2026-55439 Aug 17, 2026
curl-minimal-debuginfo · amzn 2023 8.21.0-5.amzn2023.0.1 ALAS2023-2026-2132 Sep 14, 2026
libcurl · RHEL 9 0:7.76.1-40.el9_8.5 RHSA-2026:55439 Aug 19, 2026
libcurl · almalinux 9 7.76.1-40.el9_8.5 ALSA-2026:55439 Aug 17, 2026
libcurl · amzn 2023 8.21.0-5.amzn2023.0.1 ALAS2023-2026-2132 Sep 14, 2026
libcurl · ol 10 0:8.12.1-4.el10_2.4 ELSA-2026-55450 Aug 17, 2026
libcurl · ol 9 0:7.76.1-40.el9_8.5 ELSA-2026-55439 Aug 17, 2026
libcurl-debuginfo · amzn 2023 8.21.0-5.amzn2023.0.1 ALAS2023-2026-2132 Sep 14, 2026
libcurl-devel · RHEL 9 0:7.76.1-40.el9_8.5 RHSA-2026:55439 Aug 19, 2026
libcurl-devel · almalinux 9 7.76.1-40.el9_8.5 ALSA-2026:55439 Aug 17, 2026
libcurl-devel · amzn 2023 8.21.0-5.amzn2023.0.1 ALAS2023-2026-2132 Sep 14, 2026
libcurl-devel · ol 10 0:8.12.1-4.el10_2.4 ELSA-2026-55450 Aug 17, 2026
libcurl-devel · ol 9 0:7.76.1-40.el9_8.5 ELSA-2026-55439 Aug 17, 2026
libcurl-minimal · RHEL 9 0:7.76.1-40.el9_8.5 RHSA-2026:55439 Aug 19, 2026
libcurl-minimal · almalinux 9 7.76.1-40.el9_8.5 ALSA-2026:55439 Aug 17, 2026
libcurl-minimal · amzn 2023 8.21.0-5.amzn2023.0.1 ALAS2023-2026-2132 Sep 14, 2026
libcurl-minimal · ol 10 0:8.12.1-4.el10_2.4 ELSA-2026-55450 Aug 17, 2026
libcurl-minimal · ol 9 0:7.76.1-40.el9_8.5 ELSA-2026-55439 Aug 17, 2026
libcurl-minimal-debuginfo · amzn 2023 8.21.0-5.amzn2023.0.1 ALAS2023-2026-2132 Sep 14, 2026
libcurl3-gnutls · Ubuntu 22.04.1 LTS (jammy) 7.81.0-1ubuntu1.25 libcurl3-gnutls 7.81.0-1ubuntu1.25 Jul 3, 2026
libcurl3-nss · Ubuntu 22.04.1 LTS (jammy) 7.81.0-1ubuntu1.25 libcurl3-nss 7.81.0-1ubuntu1.25 Jul 3, 2026
libcurl3t64-gnutls · Ubuntu 24.04.5 LTS (noble) 8.5.0-2ubuntu10.10 libcurl3t64-gnutls 8.5.0-2ubuntu10.10 Jul 3, 2026
libcurl3t64-gnutls · Ubuntu 25.10 (questing) 8.14.1-2ubuntu1.4 libcurl3t64-gnutls 8.14.1-2ubuntu1.4 Jul 3, 2026
libcurl3t64-gnutls · Ubuntu 26.04.1 LTS (resolute) 8.18.0-1ubuntu2.2 libcurl3t64-gnutls 8.18.0-1ubuntu2.2 Jun 26, 2026
libcurl4 · Ubuntu 22.04.1 LTS (jammy) 7.81.0-1ubuntu1.25 libcurl4 7.81.0-1ubuntu1.25 Jul 3, 2026
libcurl4t64 · Ubuntu 24.04.5 LTS (noble) 8.5.0-2ubuntu10.10 libcurl4t64 8.5.0-2ubuntu10.10 Jul 3, 2026
libcurl4t64 · Ubuntu 25.10 (questing) 8.14.1-2ubuntu1.4 libcurl4t64 8.14.1-2ubuntu1.4 Jul 3, 2026
libcurl4t64 · Ubuntu 26.04.1 LTS (resolute) 8.18.0-1ubuntu2.2 libcurl4t64 8.18.0-1ubuntu2.2 Jun 26, 2026

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