CVE-2026-3783When 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.
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No exploitation reported and no EPSS estimate yet.
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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
- 5.3 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- Weakness (CWE)
- CWE-522
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Modified
- Record last updated
- Sep 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
haxx curl haxx:curl | from 7.33.0 before 8.19.0 | NVD |
References
- https://curl.se/docs/CVE-2026-3783.htmlpatch, vendor-advisory
- https://curl.se/docs/CVE-2026-3783.jsonvendor-advisory
- https://hackerone.com/reports/3583983exploit, issue-tracking, third-party-advisory
- http://www.openwall.com/lists/oss-security/2026/03/11/2mailing-list, third-party-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.