HIGHVulnerability

CVE-2026-9545

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uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate.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

Properties

severity
HIGH
score
7.5
epss_score
0.00268
cve_id
CVE-2026-9545
signal_observed_at
2026-09-15T07:22:04+00:00
vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
published_at
2026-07-03T07:16:25.807
last_modified
2026-09-15T07:16:34.947
epss_percentile
0.19033

Related Entities (4)

ENRICHED_BY (1)

[Source]FIRST EPSS

AFFECTS_PRODUCT (1)

[Product]

HAS_WEAKNESS (1)

[Weakness]Exposure of Sensitive Information to an Unauthorized Actor

DESCRIBED_BY (1)

[Source]NVD

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CVE-2026-9545 — Ninja Signal Threat Intelligence | Ninja Signal