Vulnerability Description
When an OAuth2 bearer token is used for an HTTP(S) transfer, and that transfer performs a redirect to a second URL, curl could leak that token to the second hostname under some circumstances. If the hostname that the first request is redirected to has information in the used .netrc file, with either of the `machine` or `default` keywords, curl would pass on the bearer token set for the first host also to the second one.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Haxx | Curl | >= 7.33.0, < 8.19.0 |
Related Weaknesses (CWE)
References
- https://curl.se/docs/CVE-2026-3783.htmlPatchVendor Advisory
- https://curl.se/docs/CVE-2026-3783.jsonVendor Advisory
- https://hackerone.com/reports/3583983ExploitIssue TrackingThird Party Advisory
- http://www.openwall.com/lists/oss-security/2026/03/11/2Mailing ListThird Party Advisory
FAQ
What is CVE-2026-3783?
CVE-2026-3783 is a vulnerability with a CVSS score of 5.3 (MEDIUM). When an OAuth2 bearer token is used for an HTTP(S) transfer, and that transfer performs a redirect to a second URL, curl could leak that token to the second hostname under some circumstances. If the ...
How severe is CVE-2026-3783?
CVE-2026-3783 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-3783?
Check the references section above for vendor advisories and patch information. Affected products include: Haxx Curl.