exposing HTTP/3 early data (curl curl)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.41 % · percentile 35 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- curl
- NVD status
- Modified
Description
In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL session (`CURLOPT_SSL_SESSIONID_CACHE` is not disabled) and early data enabled (the `CURLSSLOPT_EARLYDATA` bit is set in `CURLOPT_SSL_OPTIONS`), libcurl might send off the second request's bytes on that new connection *before* enforcing the certificate verification failure. Potentially leaking sensitive information.
Weaknesses (CWE)
- CWE-200 — Exposure of Sensitive Information to an Unauthorized Actor
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | CISA-ADP |
| CVSS 3.1 | HIGH 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
European references
- ENISA EUVD · EUVD-2026-41493
- GCVE · GCVE-0-2026-9545
CERT-FR advisories
- CERTFR-2026-AVI-1390 — Multiples vulnérabilités dans Tenable Network Monitor · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1351 — Multiples vulnérabilités dans Oracle MySQL · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1281 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0797 — Multiples vulnérabilités dans cURL et libcurl · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*≥ 8.11.0 < 8.21.0
Affected products
| Product | Versions |
|---|---|
| curl · curl | affected 8.11.0 < 8.14.2 ; affected 8.15.0 < 8.16.1 ; affected 8.17.0 < 8.20.1 |
| curl · curl | affected 962097b8dd44ed5b9e7984bc1cdffdbdd566857f < 7b9613fa9b1a5e04301a3920eef58e8138dad05e |
| curl · curl | affected 8.20.0 ; affected 8.19.0 ; affected 8.18.0 ; affected 8.17.0 ; affected 8.16.0 ; affected 8.15.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |