CVE-2026-6276: curl · Origin Validation Error
Affects curlSource GCVE Database
Not known to be exploited · CVSS 7.5 High.
Data as of 11 Nov 2026, 23:17 UTC
Thin evidence
One scorer or none| CISA-ADP | CVSS 3.1 | 7.5 |
|---|
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 13 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| curl curl | Affected
| Fixed in– |
AI-suggested
Until a fix is available, users should avoid reusing the same easy handle for requests with different Host headers or manually clear or reset cookie and header state between requests to prevent cookie leakage.
Description
CVE-2026-6276 is a vulnerability in libcurl where using a custom Host header in an HTTP request causes subsequent requests on the same easy handle without that header to reuse stale cookie information from the first host. This leads to unintended cookie leakage between requests.