Vulnerability · Published Jul 3, 2026 · Assigned by curl
CVE-2026-8458wrong reuse for different services
Medium 6.5
In plain English
A medium-severity security flaw in curl from curl. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different "services". libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different services.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | curl | 8.12.1-4.el10_2.6 | ALSA-2026:69125 |
| AlmaLinux:8 | curl | 7.61.1-34.el8_10.18 | ALSA-2026:92368 |
| AlmaLinux:9 | curl | 7.76.1-40.el9_8.7 | ALSA-2026:69126 |
| AlmaLinux:9 | curl-minimal | 7.76.1-40.el9_8.7 | ALSA-2026:69126 |
| AlmaLinux:10 | libcurl | 8.12.1-4.el10_2.6 | ALSA-2026:69125 |
| AlmaLinux:8 | libcurl | 7.61.1-34.el8_10.18 | ALSA-2026:92368 |
| AlmaLinux:9 | libcurl | 7.76.1-40.el9_8.7 | ALSA-2026:69126 |
| AlmaLinux:10 | libcurl-devel | 8.12.1-4.el10_2.6 | ALSA-2026:69125 |
| AlmaLinux:8 | libcurl-devel | 7.61.1-34.el8_10.18 | ALSA-2026:92368 |
| AlmaLinux:9 | libcurl-devel | 7.76.1-40.el9_8.7 | ALSA-2026:69126 |
| AlmaLinux:10 | libcurl-minimal | 8.12.1-4.el10_2.6 | ALSA-2026:69125 |
| AlmaLinux:8 | libcurl-minimal | 7.61.1-34.el8_10.18 | ALSA-2026:92368 |
| AlmaLinux:9 | libcurl-minimal | 7.76.1-40.el9_8.7 | ALSA-2026:69126 |
| Alpine:v3.23 | curl | 8.22.0-r0 | ALPINE-CVE-2026-8458 |
| Alpine:v3.24 | curl | 8.21.0-r0 | ALPINE-CVE-2026-8458 |
| Debian:12 | curl | no fix listed | DEBIAN-CVE-2026-8458 |
| Debian:13 | curl | no fix listed | DEBIAN-CVE-2026-8458 |
| Debian:14 | curl | 8.21.0~rc2-1 | DEBIAN-CVE-2026-8458 |
| Rocky Linux:10 | curl | 0:8.12.1-4.el10_2.6 | RLSA-2026:69125 |
| Rocky Linux:8 | curl | 0:7.61.1-34.el8_10.18 | RLSA-2026:92368 |
| Rocky Linux:9 | curl | 0:7.76.1-40.el9_8.7 | RLSA-2026:69126 |
| Ubuntu:22.04:LTS | curl | 7.81.0-1ubuntu1.25 | UBUNTU-CVE-2026-8458 |
| Ubuntu:24.04:LTS | curl | 8.5.0-2ubuntu10.10 | UBUNTU-CVE-2026-8458 |
| Ubuntu:25.10 | curl | 8.14.1-2ubuntu1.4 | UBUNTU-CVE-2026-8458 |
| Ubuntu:26.04:LTS | curl | 8.18.0-1ubuntu2.2 | UBUNTU-CVE-2026-8458 |
Affected products (as reported)
Weakness: CWE-488 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N