CVE-2026-8458libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different "services".
Updated under an hour ago ()
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It affects haxx curl. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- CVSS
- 6.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
- Weakness (CWE)
- CWE-488
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Modified
- Record last updated
- Sep 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
haxx curl haxx:curl | from 7.46.0 before 8.20.0 | NVD |
References
- https://curl.se/docs/CVE-2026-8458.htmlpatch, vendor-advisory
- https://curl.se/docs/CVE-2026-8458.jsonvendor-advisory
- https://hackerone.com/reports/3721183exploit, issue-tracking, third-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.