CVE-2026-8458 - Vulnerability Details

- wrong reuse for different services

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.

Published: 2026-07-03

Score: 6.5 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

curl

unaffected

Version	Status	Constraints
`8.20.0`	affected	≤ 8.20.0
`8.19.0`	affected	≤ 8.19.0
`8.18.0`	affected	≤ 8.18.0
`8.17.0`	affected	≤ 8.17.0
`8.16.0`	affected	≤ 8.16.0
`8.15.0`	affected	≤ 8.15.0
`8.14.1`	affected	≤ 8.14.1
`8.14.0`	affected	≤ 8.14.0
`8.13.0`	affected	≤ 8.13.0
`8.12.1`	affected	≤ 8.12.1
`8.12.0`	affected	≤ 8.12.0
`8.11.1`	affected	≤ 8.11.1
`8.11.0`	affected	≤ 8.11.0
`8.10.1`	affected	≤ 8.10.1
`8.10.0`	affected	≤ 8.10.0
`8.9.1`	affected	≤ 8.9.1
`8.9.0`	affected	≤ 8.9.0
`8.8.0`	affected	≤ 8.8.0
`8.7.1`	affected	≤ 8.7.1
`8.7.0`	affected	≤ 8.7.0
`8.6.0`	affected	≤ 8.6.0
`8.5.0`	affected	≤ 8.5.0
`8.4.0`	affected	≤ 8.4.0
`8.3.0`	affected	≤ 8.3.0
`8.2.1`	affected	≤ 8.2.1
`8.2.0`	affected	≤ 8.2.0
`8.1.2`	affected	≤ 8.1.2
`8.1.1`	affected	≤ 8.1.1
`8.1.0`	affected	≤ 8.1.0
`8.0.1`	affected	≤ 8.0.1
`8.0.0`	affected	≤ 8.0.0
`7.88.1`	affected	≤ 7.88.1
`7.88.0`	affected	≤ 7.88.0
`7.87.0`	affected	≤ 7.87.0
`7.86.0`	affected	≤ 7.86.0
`7.85.0`	affected	≤ 7.85.0
`7.84.0`	affected	≤ 7.84.0
`7.83.1`	affected	≤ 7.83.1
`7.83.0`	affected	≤ 7.83.0
`7.82.0`	affected	≤ 7.82.0
`7.81.0`	affected	≤ 7.81.0
`7.80.0`	affected	≤ 7.80.0
`7.79.1`	affected	≤ 7.79.1
`7.79.0`	affected	≤ 7.79.0
`7.78.0`	affected	≤ 7.78.0
`7.77.0`	affected	≤ 7.77.0
`7.76.1`	affected	≤ 7.76.1
`7.76.0`	affected	≤ 7.76.0
`7.75.0`	affected	≤ 7.75.0
`7.74.0`	affected	≤ 7.74.0
`7.73.0`	affected	≤ 7.73.0
`7.72.0`	affected	≤ 7.72.0
`7.71.1`	affected	≤ 7.71.1
`7.71.0`	affected	≤ 7.71.0
`7.70.0`	affected	≤ 7.70.0
`7.69.1`	affected	≤ 7.69.1
`7.69.0`	affected	≤ 7.69.0
`7.68.0`	affected	≤ 7.68.0
`7.67.0`	affected	≤ 7.67.0
`7.66.0`	affected	≤ 7.66.0
`7.65.3`	affected	≤ 7.65.3
`7.65.2`	affected	≤ 7.65.2
`7.65.1`	affected	≤ 7.65.1
`7.65.0`	affected	≤ 7.65.0
`7.64.1`	affected	≤ 7.64.1
`7.64.0`	affected	≤ 7.64.0
`7.63.0`	affected	≤ 7.63.0
`7.62.0`	affected	≤ 7.62.0
`7.61.1`	affected	≤ 7.61.1
`7.61.0`	affected	≤ 7.61.0
`7.60.0`	affected	≤ 7.60.0
`7.59.0`	affected	≤ 7.59.0
`7.58.0`	affected	≤ 7.58.0
`7.57.0`	affected	≤ 7.57.0
`7.56.1`	affected	≤ 7.56.1
`7.56.0`	affected	≤ 7.56.0
`7.55.1`	affected	≤ 7.55.1
`7.55.0`	affected	≤ 7.55.0
`7.54.1`	affected	≤ 7.54.1
`7.54.0`	affected	≤ 7.54.0
`7.53.1`	affected	≤ 7.53.1
`7.53.0`	affected	≤ 7.53.0
`7.52.1`	affected	≤ 7.52.1
`7.52.0`	affected	≤ 7.52.0
`7.51.0`	affected	≤ 7.51.0
`7.50.3`	affected	≤ 7.50.3
`7.50.2`	affected	≤ 7.50.2
`7.50.1`	affected	≤ 7.50.1
`7.50.0`	affected	≤ 7.50.0
`7.49.1`	affected	≤ 7.49.1
`7.49.0`	affected	≤ 7.49.0
`7.48.0`	affected	≤ 7.48.0
`7.47.1`	affected	≤ 7.47.1
`7.47.0`	affected	≤ 7.47.0
`7.46.0`	affected	≤ 7.46.0
`7.45.0`	affected	≤ 7.45.0
`7.44.0`	affected	≤ 7.44.0
`7.43.0`	affected	≤ 7.43.0

No data.

Vendor Product Confidence Versions

Curl

100%

Version	Status	Scheme	Platform
`[0,8.20.0]`	affected	semver	—
`[0,8.19.0]`	affected	semver	—
`[0,8.18.0]`	affected	semver	—
`[0,8.17.0]`	affected	semver	—
`[0,8.16.0]`	affected	semver	—
`[0,8.15.0]`	affected	semver	—
`[0,8.14.1]`	affected	semver	—
`[0,8.14.0]`	affected	semver	—
`[0,8.13.0]`	affected	semver	—
`[0,8.12.1]`	affected	semver	—
`[0,8.12.0]`	affected	semver	—
`[0,8.11.1]`	affected	semver	—
`[0,8.11.0]`	affected	semver	—
`[0,8.10.1]`	affected	semver	—
`[0,8.10.0]`	affected	semver	—
`[0,8.9.1]`	affected	semver	—
`[0,8.9.0]`	affected	semver	—
`[0,8.8.0]`	affected	semver	—
`[0,8.7.1]`	affected	semver	—
`[0,8.7.0]`	affected	semver	—
`[0,8.6.0]`	affected	semver	—
`[0,8.5.0]`	affected	semver	—
`[0,8.4.0]`	affected	semver	—
`[0,8.3.0]`	affected	semver	—
`[0,8.2.1]`	affected	semver	—
`[0,8.2.0]`	affected	semver	—
`[0,8.1.2]`	affected	semver	—
`[0,8.1.1]`	affected	semver	—
`[0,8.1.0]`	affected	semver	—
`[0,8.0.1]`	affected	semver	—
`[0,8.0.0]`	affected	semver	—
`[0,7.88.1]`	affected	semver	—
`[0,7.88.0]`	affected	semver	—
`[0,7.87.0]`	affected	semver	—
`[0,7.86.0]`	affected	semver	—
`[0,7.85.0]`	affected	semver	—
`[0,7.84.0]`	affected	semver	—
`[0,7.83.1]`	affected	semver	—
`[0,7.83.0]`	affected	semver	—
`[0,7.82.0]`	affected	semver	—
`[0,7.81.0]`	affected	semver	—
`[0,7.80.0]`	affected	semver	—
`[0,7.79.1]`	affected	semver	—
`[0,7.79.0]`	affected	semver	—
`[0,7.78.0]`	affected	semver	—
`[0,7.77.0]`	affected	semver	—
`[0,7.76.1]`	affected	semver	—
`[0,7.76.0]`	affected	semver	—
`[0,7.75.0]`	affected	semver	—
`[0,7.74.0]`	affected	semver	—
`[0,7.73.0]`	affected	semver	—
`[0,7.72.0]`	affected	semver	—
`[0,7.71.1]`	affected	semver	—
`[0,7.71.0]`	affected	semver	—
`[0,7.70.0]`	affected	semver	—
`[0,7.69.1]`	affected	semver	—
`[0,7.69.0]`	affected	semver	—
`[0,7.68.0]`	affected	semver	—
`[0,7.67.0]`	affected	semver	—
`[0,7.66.0]`	affected	semver	—
`[0,7.65.3]`	affected	semver	—
`[0,7.65.2]`	affected	semver	—
`[0,7.65.1]`	affected	semver	—
`[0,7.65.0]`	affected	semver	—
`[0,7.64.1]`	affected	semver	—
`[0,7.64.0]`	affected	semver	—
`[0,7.63.0]`	affected	semver	—
`[0,7.62.0]`	affected	semver	—
`[0,7.61.1]`	affected	semver	—
`[0,7.61.0]`	affected	semver	—
`[0,7.60.0]`	affected	semver	—
`[0,7.59.0]`	affected	semver	—
`[0,7.58.0]`	affected	semver	—
`[0,7.57.0]`	affected	semver	—
`[0,7.56.1]`	affected	semver	—
`[0,7.56.0]`	affected	semver	—
`[0,7.55.1]`	affected	semver	—
`[0,7.55.0]`	affected	semver	—
`[0,7.54.1]`	affected	semver	—
`[0,7.54.0]`	affected	semver	—
`[0,7.53.1]`	affected	semver	—
`[0,7.53.0]`	affected	semver	—
`[0,7.52.1]`	affected	semver	—
`[0,7.52.0]`	affected	semver	—
`[0,7.51.0]`	affected	semver	—
`[0,7.50.3]`	affected	semver	—
`[0,7.50.2]`	affected	semver	—
`[0,7.50.1]`	affected	semver	—
`[0,7.50.0]`	affected	semver	—
`[0,7.49.1]`	affected	semver	—
`[0,7.49.0]`	affected	semver	—
`[0,7.48.0]`	affected	semver	—
`[0,7.47.1]`	affected	semver	—
`[0,7.47.0]`	affected	semver	—
`[0,7.46.0]`	affected	semver	—
`[0,7.45.0]`	affected	semver	—
`[0,7.44.0]`	affected	semver	—
`[0,7.43.0]`	affected	semver	—

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Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

Source	ID	Title
Ubuntu USN	USN-8487-1	curl vulnerabilities

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00206.

Exploitation poc

Automatable no

Technical Impact partial

References

Link	Providers
https://curl.se/docs/CVE-2026-8458.html
https://curl.se/docs/CVE-2026-8458.json
https://hackerone.com/reports/3721183

History

Tue, 07 Jul 2026 12:30:00 +0000

Type	Values Removed	Values Added
Weaknesses	CWE-269 CWE-285

Mon, 06 Jul 2026 22:45:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-269 CWE-285

Mon, 06 Jul 2026 18:30:00 +0000

Type	Values Removed	Values Added
Metrics		cvssV3_1 `{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N'}` ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Mon, 06 Jul 2026 13:30:00 +0000

Type	Values Removed	Values Added
Weaknesses	CWE-640

Mon, 06 Jul 2026 01:45:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-640

Sun, 05 Jul 2026 20:45:00 +0000

Type	Values Removed	Values Added
Weaknesses	CWE-287

Sun, 05 Jul 2026 12:30:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-287

Sun, 05 Jul 2026 01:15:00 +0000

Type	Values Removed	Values Added
Weaknesses	CWE-287

Sat, 04 Jul 2026 09:45:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-287

Sat, 04 Jul 2026 05:15:00 +0000

Type	Values Removed	Values Added
Weaknesses	CWE-285

Fri, 03 Jul 2026 17:45:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-285

Fri, 03 Jul 2026 08:00:00 +0000

Type	Values Removed	Values Added
First Time appeared		Curl Curl curl
Vendors & Products		Curl Curl curl

Fri, 03 Jul 2026 06:45:00 +0000

Type	Values Removed	Values Added
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.
Title		wrong reuse for different services
References		https://curl.se/docs/CVE-2026-8458.html https://curl.se/docs/CVE-2026-8458.json https://hackerone.com/reports/3721183

Subscriptions

Curl Curl

MITRE

Status: PUBLISHED

Assigner: curl

Published: 2026-07-03T06:14:42.258Z

Updated: 2026-07-06T17:32:06.018Z

Reserved: 2026-05-13T08:33:36.632Z

Link: CVE-2026-8458

Vulnrichment

Updated: 2026-07-06T17:31:59.712Z

NVD

No data.

Redhat

No data.

OpenCVE Enrichment

Updated: 2026-07-07T12:15:06Z

Weaknesses

No weakness.

Tracking

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact High

Availability Impact None

User Interaction None

Exploitation poc

Automatable no

Technical Impact partial

Subscriptions

JSON object

JSON object

JSON object

JSON object

JSON object