6.5
MEDIUM
CVSS 3.1
CVE-2026-8458
wrong reuse for different services
Overview
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.
Details
INFO
Published Date :
July 3, 2026, 7:16 a.m.
Last Modified :
July 7, 2026, 11:12 p.m.
Remotely Exploit :
Yes !
Source :
2499f714-1537-4658-8207-48ae4bb9eae9
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework
for assessing the severity of vulnerabilities in software and systems.
We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | MEDIUM | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
Update libcurl to fix a logical error in connection reuse for Negotiate authentication.
- Update libcurl to the latest version.
- Review authentication configurations.
- Test connection reuse logic.
References
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-8458.
| URL | Resource |
|---|---|
| https://curl.se/docs/CVE-2026-8458.html | Patch Vendor Advisory |
| https://curl.se/docs/CVE-2026-8458.json | Vendor Advisory |
| https://hackerone.com/reports/3721183 | Exploit Issue Tracking Third Party Advisory |
| https://hackerone.com/reports/3721183 | Exploit Issue Tracking Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-8458 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-8458
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-8458 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-8458 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 07, 2026
Action Type Old Value New Value Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:* versions from (including) 7.46.0 up to (excluding) 8.20.0 Added Reference Type curl: https://curl.se/docs/CVE-2026-8458.html Types: Patch, Vendor Advisory Added Reference Type curl: https://curl.se/docs/CVE-2026-8458.json Types: Vendor Advisory Added Reference Type curl: https://hackerone.com/reports/3721183 Types: Exploit, Issue Tracking, Third Party Advisory Added Reference Type CISA-ADP: https://hackerone.com/reports/3721183 Types: Exploit, Issue Tracking, Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 06, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N Added Reference https://hackerone.com/reports/3721183 Added SSVC {'id': 'CVE-2026-8458', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-06T17:31:14.007899Z'} -
New CVE Received by 2499f714-1537-4658-8207-48ae4bb9eae9
Jul. 03, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'curl', 'product': 'curl', 'versions': [{'status': 'affected', 'version': '8.20.0', 'versionType': 'semver', 'lessThanOrEqual': '8.20.0'}, {'status': 'affected', 'version': '8.19.0', 'versionType': 'semver', 'lessThanOrEqual': '8.19.0'}, {'status': 'affected', 'version': '8.18.0', 'versionType': 'semver', 'lessThanOrEqual': '8.18.0'}, {'status': 'affected', 'version': '8.17.0', 'versionType': 'semver', 'lessThanOrEqual': '8.17.0'}, {'status': 'affected', 'version': '8.16.0', 'versionType': 'semver', 'lessThanOrEqual': '8.16.0'}, {'status': 'affected', 'version': '8.15.0', 'versionType': 'semver', 'lessThanOrEqual': '8.15.0'}, {'status': 'affected', 'version': '8.14.1', 'versionType': 'semver', 'lessThanOrEqual': '8.14.1'}, {'status': 'affected', 'version': '8.14.0', 'versionType': 'semver', 'lessThanOrEqual': '8.14.0'}, {'status': 'affected', 'version': '8.13.0', 'versionType': 'semver', 'lessThanOrEqual': '8.13.0'}, {'status': 'affected', 'version': '8.12.1', 'versionType': 'semver', 'lessThanOrEqual': '8.12.1'}, {'status': 'affected', 'version': '8.12.0', 'versionType': 'semver', 'lessThanOrEqual': '8.12.0'}, {'status': 'affected', 'version': '8.11.1', 'versionType': 'semver', 'lessThanOrEqual': '8.11.1'}, {'status': 'affected', 'version': '8.11.0', 'versionType': 'semver', 'lessThanOrEqual': '8.11.0'}, {'status': 'affected', 'version': '8.10.1', 'versionType': 'semver', 'lessThanOrEqual': '8.10.1'}, {'status': 'affected', 'version': '8.10.0', 'versionType': 'semver', 'lessThanOrEqual': '8.10.0'}, {'status': 'affected', 'version': '8.9.1', 'versionType': 'semver', 'lessThanOrEqual': '8.9.1'}, {'status': 'affected', 'version': '8.9.0', 'versionType': 'semver', 'lessThanOrEqual': '8.9.0'}, {'status': 'affected', 'version': '8.8.0', 'versionType': 'semver', 'lessThanOrEqual': '8.8.0'}, {'status': 'affected', 'version': '8.7.1', 'versionType': 'semver', 'lessThanOrEqual': '8.7.1'}, {'status': 'affected', 'version': '8.7.0', 'versionType': 'semver', 'lessThanOrEqual': '8.7.0'}, {'status': 'affected', 'version': '8.6.0', 'versionType': 'semver', 'lessThanOrEqual': '8.6.0'}, {'status': 'affected', 'version': '8.5.0', 'versionType': 'semver', 'lessThanOrEqual': '8.5.0'}, {'status': 'affected', 'version': '8.4.0', 'versionType': 'semver', 'lessThanOrEqual': '8.4.0'}, {'status': 'affected', 'version': '8.3.0', 'versionType': 'semver', 'lessThanOrEqual': '8.3.0'}, {'status': 'affected', 'version': '8.2.1', 'versionType': 'semver', 'lessThanOrEqual': '8.2.1'}, {'status': 'affected', 'version': '8.2.0', 'versionType': 'semver', 'lessThanOrEqual': '8.2.0'}, {'status': 'affected', 'version': '8.1.2', 'versionType': 'semver', 'lessThanOrEqual': '8.1.2'}, {'status': 'affected', 'version': '8.1.1', 'versionType': 'semver', 'lessThanOrEqual': '8.1.1'}, {'status': 'affected', 'version': '8.1.0', 'versionType': 'semver', 'lessThanOrEqual': '8.1.0'}, {'status': 'affected', 'version': '8.0.1', 'versionType': 'semver', 'lessThanOrEqual': '8.0.1'}, {'status': 'affected', 'version': '8.0.0', 'versionType': 'semver', 'lessThanOrEqual': '8.0.0'}, {'status': 'affected', 'version': '7.88.1', 'versionType': 'semver', 'lessThanOrEqual': '7.88.1'}, {'status': 'affected', 'version': '7.88.0', 'versionType': 'semver', 'lessThanOrEqual': '7.88.0'}, {'status': 'affected', 'version': '7.87.0', 'versionType': 'semver', 'lessThanOrEqual': '7.87.0'}, {'status': 'affected', 'version': '7.86.0', 'versionType': 'semver', 'lessThanOrEqual': '7.86.0'}, {'status': 'affected', 'version': '7.85.0', 'versionType': 'semver', 'lessThanOrEqual': '7.85.0'}, {'status': 'affected', 'version': '7.84.0', 'versionType': 'semver', 'lessThanOrEqual': '7.84.0'}, {'status': 'affected', 'version': '7.83.1', 'versionType': 'semver', 'lessThanOrEqual': '7.83.1'}, {'status': 'affected', 'version': '7.83.0', 'versionType': 'semver', 'lessThanOrEqual': '7.83.0'}, {'status': 'affected', 'version': '7.82.0', 'versionType': 'semver', 'lessThanOrEqual': '7.82.0'}, {'status': 'affected', 'version': '7.81.0', 'versionType': 'semver', 'lessThanOrEqual': '7.81.0'}, {'status': 'affected', 'version': '7.80.0', 'versionType': 'semver', 'lessThanOrEqual': '7.80.0'}, {'status': 'affected', 'version': '7.79.1', 'versionType': 'semver', 'lessThanOrEqual': '7.79.1'}, {'status': 'affected', 'version': '7.79.0', 'versionType': 'semver', 'lessThanOrEqual': '7.79.0'}, {'status': 'affected', 'version': '7.78.0', 'versionType': 'semver', 'lessThanOrEqual': '7.78.0'}, {'status': 'affected', 'version': '7.77.0', 'versionType': 'semver', 'lessThanOrEqual': '7.77.0'}, {'status': 'affected', 'version': '7.76.1', 'versionType': 'semver', 'lessThanOrEqual': '7.76.1'}, {'status': 'affected', 'version': '7.76.0', 'versionType': 'semver', 'lessThanOrEqual': '7.76.0'}, {'status': 'affected', 'version': '7.75.0', 'versionType': 'semver', 'lessThanOrEqual': '7.75.0'}, {'status': 'affected', 'version': '7.74.0', 'versionType': 'semver', 'lessThanOrEqual': '7.74.0'}, {'status': 'affected', 'version': '7.73.0', 'versionType': 'semver', 'lessThanOrEqual': '7.73.0'}, {'status': 'affected', 'version': '7.72.0', 'versionType': 'semver', 'lessThanOrEqual': '7.72.0'}, {'status': 'affected', 'version': '7.71.1', 'versionType': 'semver', 'lessThanOrEqual': '7.71.1'}, {'status': 'affected', 'version': '7.71.0', 'versionType': 'semver', 'lessThanOrEqual': '7.71.0'}, {'status': 'affected', 'version': '7.70.0', 'versionType': 'semver', 'lessThanOrEqual': '7.70.0'}, {'status': 'affected', 'version': '7.69.1', 'versionType': 'semver', 'lessThanOrEqual': '7.69.1'}, {'status': 'affected', 'version': '7.69.0', 'versionType': 'semver', 'lessThanOrEqual': '7.69.0'}, {'status': 'affected', 'version': '7.68.0', 'versionType': 'semver', 'lessThanOrEqual': '7.68.0'}, {'status': 'affected', 'version': '7.67.0', 'versionType': 'semver', 'lessThanOrEqual': '7.67.0'}, {'status': 'affected', 'version': '7.66.0', 'versionType': 'semver', 'lessThanOrEqual': '7.66.0'}, {'status': 'affected', 'version': '7.65.3', 'versionType': 'semver', 'lessThanOrEqual': '7.65.3'}, {'status': 'affected', 'version': '7.65.2', 'versionType': 'semver', 'lessThanOrEqual': '7.65.2'}, {'status': 'affected', 'version': '7.65.1', 'versionType': 'semver', 'lessThanOrEqual': '7.65.1'}, {'status': 'affected', 'version': '7.65.0', 'versionType': 'semver', 'lessThanOrEqual': '7.65.0'}, {'status': 'affected', 'version': '7.64.1', 'versionType': 'semver', 'lessThanOrEqual': '7.64.1'}, {'status': 'affected', 'version': '7.64.0', 'versionType': 'semver', 'lessThanOrEqual': '7.64.0'}, {'status': 'affected', 'version': '7.63.0', 'versionType': 'semver', 'lessThanOrEqual': '7.63.0'}, {'status': 'affected', 'version': '7.62.0', 'versionType': 'semver', 'lessThanOrEqual': '7.62.0'}, {'status': 'affected', 'version': '7.61.1', 'versionType': 'semver', 'lessThanOrEqual': '7.61.1'}, {'status': 'affected', 'version': '7.61.0', 'versionType': 'semver', 'lessThanOrEqual': '7.61.0'}, {'status': 'affected', 'version': '7.60.0', 'versionType': 'semver', 'lessThanOrEqual': '7.60.0'}, {'status': 'affected', 'version': '7.59.0', 'versionType': 'semver', 'lessThanOrEqual': '7.59.0'}, {'status': 'affected', 'version': '7.58.0', 'versionType': 'semver', 'lessThanOrEqual': '7.58.0'}, {'status': 'affected', 'version': '7.57.0', 'versionType': 'semver', 'lessThanOrEqual': '7.57.0'}, {'status': 'affected', 'version': '7.56.1', 'versionType': 'semver', 'lessThanOrEqual': '7.56.1'}, {'status': 'affected', 'version': '7.56.0', 'versionType': 'semver', 'lessThanOrEqual': '7.56.0'}, {'status': 'affected', 'version': '7.55.1', 'versionType': 'semver', 'lessThanOrEqual': '7.55.1'}, {'status': 'affected', 'version': '7.55.0', 'versionType': 'semver', 'lessThanOrEqual': '7.55.0'}, {'status': 'affected', 'version': '7.54.1', 'versionType': 'semver', 'lessThanOrEqual': '7.54.1'}, {'status': 'affected', 'version': '7.54.0', 'versionType': 'semver', 'lessThanOrEqual': '7.54.0'}, {'status': 'affected', 'version': '7.53.1', 'versionType': 'semver', 'lessThanOrEqual': '7.53.1'}, {'status': 'affected', 'version': '7.53.0', 'versionType': 'semver', 'lessThanOrEqual': '7.53.0'}, {'status': 'affected', 'version': '7.52.1', 'versionType': 'semver', 'lessThanOrEqual': '7.52.1'}, {'status': 'affected', 'version': '7.52.0', 'versionType': 'semver', 'lessThanOrEqual': '7.52.0'}, {'status': 'affected', 'version': '7.51.0', 'versionType': 'semver', 'lessThanOrEqual': '7.51.0'}, {'status': 'affected', 'version': '7.50.3', 'versionType': 'semver', 'lessThanOrEqual': '7.50.3'}, {'status': 'affected', 'version': '7.50.2', 'versionType': 'semver', 'lessThanOrEqual': '7.50.2'}, {'status': 'affected', 'version': '7.50.1', 'versionType': 'semver', 'lessThanOrEqual': '7.50.1'}, {'status': 'affected', 'version': '7.50.0', 'versionType': 'semver', 'lessThanOrEqual': '7.50.0'}, {'status': 'affected', 'version': '7.49.1', 'versionType': 'semver', 'lessThanOrEqual': '7.49.1'}, {'status': 'affected', 'version': '7.49.0', 'versionType': 'semver', 'lessThanOrEqual': '7.49.0'}, {'status': 'affected', 'version': '7.48.0', 'versionType': 'semver', 'lessThanOrEqual': '7.48.0'}, {'status': 'affected', 'version': '7.47.1', 'versionType': 'semver', 'lessThanOrEqual': '7.47.1'}, {'status': 'affected', 'version': '7.47.0', 'versionType': 'semver', 'lessThanOrEqual': '7.47.0'}, {'status': 'affected', 'version': '7.46.0', 'versionType': 'semver', 'lessThanOrEqual': '7.46.0'}, {'status': 'affected', 'version': '7.45.0', 'versionType': 'semver', 'lessThanOrEqual': '7.45.0'}, {'status': 'affected', 'version': '7.44.0', 'versionType': 'semver', 'lessThanOrEqual': '7.44.0'}, {'status': 'affected', 'version': '7.43.0', 'versionType': 'semver', 'lessThanOrEqual': '7.43.0'}], 'defaultStatus': 'unaffected'}] 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. Added Reference https://curl.se/docs/CVE-2026-8458.html Added Reference https://curl.se/docs/CVE-2026-8458.json Added Reference https://hackerone.com/reports/3721183
EPSS is a daily estimate of the probability of exploitation activity
being observed over the next 30 days. Following chart shows the EPSS
score history of the vulnerability.