CVE-2026-8458
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…
Does this matter?
Lower severity and a low EPSS score (0.54%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.54% probability · 44th percentile
- CISA KEV
- Not listed
- Affected
- haxx/curl
- Source
- 2499f714-1537-4658-8207-48ae4bb9eae9
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
- https://hackerone.com/reports/3721183Exploit, Issue Tracking, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.