CVE-2026-8458

wrong reuse for different services

MEDIUM
6.5
CVSS Score
Published: July 3, 2026 at 06:14 AM UTC
Updated: September 15, 2026 at 07:35 AM UTC
1 product affected across 1 vendorCurl

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Severity
MEDIUM6.5
Exploit prediction
EPSS 0.4%
SSVC
PoC

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

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 5e99b73cf441d9c369768b9cd48b5389b9a2503d (fixed)
Affected range stops below 8.14.2, so it looks safe — our inference, not a vendor statement
Affected range stops below 8.16.1, so it looks safe — our inference, not a vendor statement
Affected range stops below 8.20.0, so it looks safe — our inference, not a vendor statement
Affected range stops below 8.20.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (3)

Vendor Advisory
Source: cverecord
https://curl.se/docs/CVE-2026-8458.json
PatchVendor Advisory
Source: cverecord
https://curl.se/docs/CVE-2026-8458.html
ExploitIssue TrackingThird Party Advisory
Source: cverecord
https://hackerone.com/reports/3721183

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.5MEDIUMCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfoCWE-488

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