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.
Affected products
haxx: curl
References4
- curl.se/docs/CVE-2026-3783.html PatchVendor Advisory
- curl.se/docs/CVE-2026-3783.json Vendor Advisory
- hackerone.com/reports/3583983 ExploitIssue TrackingThird Party Advisory
- www.openwall.com/lists/oss-security/2026/03/11/2 Mailing ListThird Party Advisory
Metrics
- CVSS 3.1
-
5.3
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - EPSS — exploit probability
- 0% percentile: 43 · as of 12 November 2026
- CWE
- CWE-522
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