VULNERABILITY INTELLIGENCE

CVE-2026-9545

CVSS score7.5 HIGH
EPSS probability0.41%
CISA KEVNot currently listed
Published2026-07-03
Last modified2026-09-15
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

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uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate.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.

Weakness classification

  • 2499f714-1537-4658-8207-48ae4bb9eae9: CWE-200
  • nvd@nist.gov: NVD-CWE-noinfo

Primary references