CVE-2026-19931Critical· 9.8▾ AbyssalPoC availableA flaw in libcurl makes it wrongly reuse an HTTP connection setup for a given hostname using Negotiate authentication, when the initial request is done using empty credentials. This can make user B's request get sent over user A's previo…
▾ Abyssal zone — Critical with a public exploit or in-the-wild use
impact 53.9 · likelihood 0.2 · exploitation 12
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.
Exploit-prediction probability, daily snapshots since Sep 7.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.3%
Exploit / PoC code exists
— → 9.8
none → critical
9.8 → —
critical → none
— → 9.8
none → critical
0.3% → 1.2%
Last analysed / modified upstream
A flaw in libcurl makes it wrongly reuse an HTTP connection setup for a given hostname using Negotiate authentication, when the initial request is done using empty credentials. This can make user B's request get sent over user A's previously authenticated connection.
curl >= 7.64.1, < 8.22.0Upgrade past the affected range:
curl 8.22.0Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-80231High· 7.5A flaw in libcurl makes it wrongly reuse an existing HTTPS connection setup for a given hostname even when using a different Native CA Store setting (`CURLSSLOPT_NATIVE_CA`) than when the connection was created.
CVE-2026-18924Critical· 9.1A flaw in libcurl's handling of HTTP/2 Server Push streams, when the parent handle is set to share connections with other handles, can lead to use-after-free in the cleanup process.
CVE-2026-13608High· 7.4A flaw in the libcurl SASL negotiation for LDAP authentication allows an incomplete handshake sequence to be misinterpreted as a successful cryptographic verification
CVE-2026-5545Medium· 6.5libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTP(S) request after a Negotiate-authenticated one, when both use the same host. libcurl features a pool of recent connections so that sub…
CVE-2026-82209High· 8.2When libpsl support is enabled, libcurl fails to enforce the Public Suffix List boundary check when processing a `Set-Cookie` header where the `Domain` attribute explicitly matches an origin host that is itself a public suffix (e.g., `Do…
CVE-2026-80230High· 7.5When `CURLOPT_PINNEDPUBLICKEY` is configured alongside options that disable standard peer verification (`CURLOPT_SSL_VERIFYPEER = 0` and `CURLOPT_SSL_VERIFYHOST = 0`), libcurl fails to enforce public key pinning on connections establishe…