# CVE-2026-1965: bad reuse of HTTP Negotiate connection

CVE-2026-1965 is fixed in 11 products on 1 platform, first by curl 7.68.0-1ubuntu2.25+esm3, released March 11, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-1965
- Priority: High
- CVSS: 8.1 (Moderate)
- EPSS: 0.0030
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Mar 11, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-1965

## Description

The curl packages provide the libcurl library and the curl utility for downloading files from servers using various protocols, including HTTP, FTP, and LDAP.  Security Fix(es):  * curl: curl: Authentication bypass due to incorrect connection reuse with Negotiate authentication (CVE-2026-1965)  * curl: curl: Information disclosure via OAuth2 bearer token leakage during HTTP(S) redirect (CVE-2026-3783)  * curl: curl: Man-in-the-middle attack via SSH host key bypass (CVE-2026-9547)  * curl: curl: Insecure connection establishment due to TLS configuration mismatch (CVE-2026-8286)  For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | curl Debian 13.5 (trixie) | 8.14.1-2+deb13u4 | [DEBIAN-CVE-2026-1965](https://patchblox.com/security/data/fix/linux/debian-cve-2026-1965.md) | Mar 11, 2026 |
| Linux | curl Debian 14 | 8.19.0~rc3-1 | [DEBIAN-CVE-2026-1965](https://patchblox.com/security/data/fix/linux/debian-cve-2026-1965.md) | Mar 11, 2026 |
| Linux | curl RHEL 10 | 8.12.1-1.el10_0.10 | [RHSA-2026:72506](https://patchblox.com/security/data/fix/linux/rhsa-2026-72506.md) | Jul 3, 2026 |
| Linux | curl RHEL 9 | 0:7.76.1-40.el9_8.5 | [RHSA-2026:55439](https://patchblox.com/security/data/fix/linux/rhsa-2026-55439.md) | Aug 19, 2026 |
| Linux | curl Ubuntu 20.04 LTS (focal) | 7.68.0-1ubuntu2.25+esm3 | [curl 7.68.0-1ubuntu2.25+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-curl-7.68.0-1ubuntu2.25-esm3.md) | Mar 11, 2026 |
| Linux | curl Ubuntu 22.04.1 LTS (jammy) | 7.81.0-1ubuntu1.23 | [curl 7.81.0-1ubuntu1.23](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-curl-7.81.0-1ubuntu1.23.md) | Mar 11, 2026 |
| Linux | curl Ubuntu 24.04.5 LTS (noble) | 8.5.0-2ubuntu10.8 | [curl 8.5.0-2ubuntu10.8](https://patchblox.com/security/data/fix/linux/ubuntu-noble-curl-8.5.0-2ubuntu10.8.md) | Mar 11, 2026 |
| Linux | curl Ubuntu 25.10 (questing) | 8.14.1-2ubuntu1.2 | [curl 8.14.1-2ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-questing-curl-8.14.1-2ubuntu1.2.md) | Mar 11, 2026 |
| Linux | curl Ubuntu 26.04.1 LTS (resolute) | 8.18.0-1ubuntu2 | [curl 8.18.0-1ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-curl-8.18.0-1ubuntu2.md) | Mar 11, 2026 |
| Linux | curl almalinux 9 | 7.76.1-40.el9_8.5 | [ALSA-2026:55439](https://patchblox.com/security/data/fix/linux/alsa-2026-55439.md) | Aug 17, 2026 |
| Linux | curl ol 10 | 0:8.12.1-4.el10_2.4 | [ELSA-2026-55450](https://patchblox.com/security/data/fix/linux/elsa-2026-55450.md) | Aug 17, 2026 |
| Linux | curl ol 9 | 0:7.76.1-40.el9_8.5 | [ELSA-2026-55439](https://patchblox.com/security/data/fix/linux/elsa-2026-55439.md) | Aug 17, 2026 |
| Linux | curl opensuse-leap 15.6 | 8.14.1-150600.4.40.1 | [SUSE-SU-2026:0885-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0885-1.md) | Mar 12, 2026 |
| Linux | curl opensuse-leap 16.0 | 8.14.1-160000.5.1 | [OPENSUSE-SU-2026:20404-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-20404-1.md) | Mar 20, 2026 |
| Linux | curl rocky 9 | 0:7.76.1-40.el9_8.5 | [RLSA-2026:55439](https://patchblox.com/security/data/fix/linux/rlsa-2026-55439.md) | Aug 17, 2026 |
| Linux | curl sles 15.6 | 8.14.1-150600.4.40.1 | [SUSE-SU-2026:0885-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0885-1.md) | Mar 12, 2026 |
| Linux | curl sles 15.7 | 8.14.1-150700.7.14.1 | [SUSE-SU-2026:0903-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-0903-1.md) | Mar 17, 2026 |
| Linux | curl sles 16.0 | 8.14.1-160000.5.1 | [SUSE-SU-2026:20918-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20918-1.md) | Mar 20, 2026 |
| Linux | curl-mini sles 16.0 | 8.14.1-160000.5.1 | [SUSE-SU-2026:20918-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-20918-1.md) | Mar 20, 2026 |
| Linux | curl-minimal RHEL 9 | 0:7.76.1-40.el9_8.5 | [RHSA-2026:55439](https://patchblox.com/security/data/fix/linux/rhsa-2026-55439.md) | Aug 19, 2026 |
| Linux | curl-minimal almalinux 9 | 7.76.1-40.el9_8.5 | [ALSA-2026:55439](https://patchblox.com/security/data/fix/linux/alsa-2026-55439.md) | Aug 17, 2026 |
| Linux | curl-minimal ol 9 | 0:7.76.1-40.el9_8.5 | [ELSA-2026-55439](https://patchblox.com/security/data/fix/linux/elsa-2026-55439.md) | Aug 17, 2026 |
| Linux | libcurl RHEL 9 | 0:7.76.1-40.el9_8.5 | [RHSA-2026:55439](https://patchblox.com/security/data/fix/linux/rhsa-2026-55439.md) | Aug 19, 2026 |
| Linux | libcurl almalinux 9 | 7.76.1-40.el9_8.5 | [ALSA-2026:55439](https://patchblox.com/security/data/fix/linux/alsa-2026-55439.md) | Aug 17, 2026 |
| Linux | libcurl ol 10 | 0:8.12.1-4.el10_2.4 | [ELSA-2026-55450](https://patchblox.com/security/data/fix/linux/elsa-2026-55450.md) | Aug 17, 2026 |
| Linux | libcurl ol 9 | 0:7.76.1-40.el9_8.5 | [ELSA-2026-55439](https://patchblox.com/security/data/fix/linux/elsa-2026-55439.md) | Aug 17, 2026 |
| Linux | libcurl-devel RHEL 9 | 0:7.76.1-40.el9_8.5 | [RHSA-2026:55439](https://patchblox.com/security/data/fix/linux/rhsa-2026-55439.md) | Aug 19, 2026 |
| Linux | libcurl-devel almalinux 9 | 7.76.1-40.el9_8.5 | [ALSA-2026:55439](https://patchblox.com/security/data/fix/linux/alsa-2026-55439.md) | Aug 17, 2026 |
| Linux | libcurl-devel ol 10 | 0:8.12.1-4.el10_2.4 | [ELSA-2026-55450](https://patchblox.com/security/data/fix/linux/elsa-2026-55450.md) | Aug 17, 2026 |
| Linux | libcurl-devel ol 9 | 0:7.76.1-40.el9_8.5 | [ELSA-2026-55439](https://patchblox.com/security/data/fix/linux/elsa-2026-55439.md) | Aug 17, 2026 |
| Linux | libcurl-minimal RHEL 9 | 0:7.76.1-40.el9_8.5 | [RHSA-2026:55439](https://patchblox.com/security/data/fix/linux/rhsa-2026-55439.md) | Aug 19, 2026 |
| Linux | libcurl-minimal almalinux 9 | 7.76.1-40.el9_8.5 | [ALSA-2026:55439](https://patchblox.com/security/data/fix/linux/alsa-2026-55439.md) | Aug 17, 2026 |
| Linux | libcurl-minimal ol 10 | 0:8.12.1-4.el10_2.4 | [ELSA-2026-55450](https://patchblox.com/security/data/fix/linux/elsa-2026-55450.md) | Aug 17, 2026 |
| Linux | libcurl-minimal ol 9 | 0:7.76.1-40.el9_8.5 | [ELSA-2026-55439](https://patchblox.com/security/data/fix/linux/elsa-2026-55439.md) | Aug 17, 2026 |
| Linux | libcurl3-gnutls Ubuntu 20.04 LTS (focal) | 7.68.0-1ubuntu2.25+esm3 | [libcurl3-gnutls 7.68.0-1ubuntu2.25+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libcurl3-gnutls-7.68.0-1ubuntu2.25-esm3.md) | Mar 11, 2026 |
| Linux | libcurl3-gnutls Ubuntu 22.04.1 LTS (jammy) | 7.81.0-1ubuntu1.23 | [libcurl3-gnutls 7.81.0-1ubuntu1.23](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libcurl3-gnutls-7.81.0-1ubuntu1.23.md) | Mar 11, 2026 |
| Linux | libcurl3-nss Ubuntu 20.04 LTS (focal) | 7.68.0-1ubuntu2.25+esm3 | [libcurl3-nss 7.68.0-1ubuntu2.25+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libcurl3-nss-7.68.0-1ubuntu2.25-esm3.md) | Mar 11, 2026 |
| Linux | libcurl3-nss Ubuntu 22.04.1 LTS (jammy) | 7.81.0-1ubuntu1.23 | [libcurl3-nss 7.81.0-1ubuntu1.23](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libcurl3-nss-7.81.0-1ubuntu1.23.md) | Mar 11, 2026 |
| Linux | libcurl3t64-gnutls Ubuntu 24.04.5 LTS (noble) | 8.5.0-2ubuntu10.8 | [libcurl3t64-gnutls 8.5.0-2ubuntu10.8](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libcurl3t64-gnutls-8.5.0-2ubuntu10.8.md) | Mar 11, 2026 |
| Linux | libcurl3t64-gnutls Ubuntu 25.10 (questing) | 8.14.1-2ubuntu1.2 | [libcurl3t64-gnutls 8.14.1-2ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-questing-libcurl3t64-gnutls-8.14.1-2ubuntu1.2.md) | Mar 11, 2026 |
| Linux | libcurl3t64-gnutls Ubuntu 26.04.1 LTS (resolute) | 8.18.0-1ubuntu2 | [libcurl3t64-gnutls 8.18.0-1ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libcurl3t64-gnutls-8.18.0-1ubuntu2.md) | Mar 11, 2026 |
| Linux | libcurl4 Ubuntu 20.04 LTS (focal) | 7.68.0-1ubuntu2.25+esm3 | [libcurl4 7.68.0-1ubuntu2.25+esm3](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libcurl4-7.68.0-1ubuntu2.25-esm3.md) | Mar 11, 2026 |
| Linux | libcurl4 Ubuntu 22.04.1 LTS (jammy) | 7.81.0-1ubuntu1.23 | [libcurl4 7.81.0-1ubuntu1.23](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libcurl4-7.81.0-1ubuntu1.23.md) | Mar 11, 2026 |
| Linux | libcurl4t64 Ubuntu 24.04.5 LTS (noble) | 8.5.0-2ubuntu10.8 | [libcurl4t64 8.5.0-2ubuntu10.8](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libcurl4t64-8.5.0-2ubuntu10.8.md) | Mar 11, 2026 |
| Linux | libcurl4t64 Ubuntu 25.10 (questing) | 8.14.1-2ubuntu1.2 | [libcurl4t64 8.14.1-2ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-questing-libcurl4t64-8.14.1-2ubuntu1.2.md) | Mar 11, 2026 |
| Linux | libcurl4t64 Ubuntu 26.04.1 LTS (resolute) | 8.18.0-1ubuntu2 | [libcurl4t64 8.18.0-1ubuntu2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libcurl4t64-8.18.0-1ubuntu2.md) | Mar 11, 2026 |

---

Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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