Connection Reuse Vulnerability in libcurl Affects Multiple Applications
CVE-2026-8458

6.5MEDIUM

Key Information:

Vendor

Curl

Status
Curl
Vendor
CVE Published:
3 July 2026

What is CVE-2026-8458?

A logical error in libcurl may lead to the improper reuse of connections in specific scenarios involving Negotiate authentication. This bug allows applications to mistakenly use a previously established connection intended for a different service, possibly compromising security. Implementing proper checks for connection criteria is critical to avoid potential exploitation of this vulnerability.

Affected Version(s)

curl 8.20.0

curl 8.19.0

curl 8.18.0

References

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

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Muhamad Arga Reksapati
Stefan Eissing
.