CVE-2026-9547High· 7.4▾ MidnightPoC availableWhen a libcurl-based application performs transfers via `SCP://` or `SFTP://` and utilizes the `CURLOPT_SSH_KEYFUNCTION` callback, it may silently accept an untrusted server. This vulnerability occurs when a server presents a host key ty…
▾ Midnight zone — Critical, or high with PoC / in-the-wild
impact 40.7 · likelihood 0.1 · 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 Jul 4.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via NVD
0.2%
0.2% → 0.5%
7.4 → —
— → 7.4
none → high
7.4 → —
high → none
— → 7.4
none → high
7.4 → —
high → none
— → 7.4
none → high
Last analysed / modified upstream
Exploit / PoC code exists
When a libcurl-based application performs transfers via SCP:// or SFTP://
and utilizes the CURLOPT_SSH_KEYFUNCTION callback, it may silently accept an
untrusted server. This vulnerability occurs when a server presents a host key
type that does not match the specific key type already recorded for that host
in the known_hosts file. Instead of rejecting the mismatch, the callback
mechanism fails to properly enforce the restriction, allowing the connection
to succeed without warning and risking a potential man-in-the-middle attack.
curl >= 7.69.0, < 8.21.0Upgrade past the affected range:
curl 8.21.0Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-12064High· 7.5When a user invokes curl using a schemeless URL combined with `--proto-default` sftp (or scp), a disconnect occurs between the tool layer and libcurl
CVE-2026-3783Medium· 5.3When 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 re…
CVE-2026-9079Critical· 9.8libcurl had a flaw that when instructed to clear proxy authentication credentials which made it not do so, leaving the old credentials around to get used for subsequent transfers that should not know nor use them.
CVE-2026-8932High· 7.5libcurl would reuse a previously created connection even when some mTLS config related option had been changed that should have prohibited reuse. libcurl keeps previously used connections in a connection pool for subsequent transfers to…
CVE-2026-8927Critical· 9.1When reusing a libcurl handle for sequential transfers driven by environment-variable proxy configuration, libcurl fails to clear the proxy authentication state between requests
CVE-2026-8924Critical· 9.1A flaw in curl’s cookie parsing logic allows a malicious HTTP server to set "super cookies" that bypass the Public Suffix List check