CVE-2026-8458Haxx Curl
NVDCVSS scored by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Vulnerability Summary
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.
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 v3.1 Base Metrics — Score 6.5 (MEDIUM)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:NAttack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeUnchanged
ConfidentialityNone
IntegrityHigh
AvailabilityNone
Affected & Patched Versions
- Haxx Curl >= 7.46.0 and < 8.20.0
- Haxx Curl 8.20.0
What to do
Prioritize this fix. Exploit code is public, so attacks can follow quickly.
- Check whether you run Haxx Curl and which version.
- Update to a patched version listed above, then confirm the new version.
- Review logs and exposed services for signs of earlier compromise.
Timeline
- Jul 3, 2026Published
- Jul 7, 2026Record last modified
Score, severity and exploitation changes are tracked from the day Watchtower started logging them.
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External References
Data last checked: Nov 14, 2026 02:13 UTC