curl: urlapi: off-by-one in custom scheme validation skips last character

Summary In lib/urlapi.c, the seturlscheme function has an off-by-one error when validating custom scheme names. The validation loop checks scheme0 twice once by ISALPHA, once in the loop and never checks the last character. This allows schemes ending with any arbitrary byte e.g., foo!, bar, bad/ ...

Use After Free

Overview Affected versions of this package are vulnerable to Use After Free in smb.c, which may reuse already freed memory from a previous SMB connection request. The window of opportunity to exploit this is small, and the region of memory exposed is small and out of the attacker's control...

EUVD-2026-11139

curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP proxy. The proper behavior is to create or use a separate connection...

EUVD-2026-11141

When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory...

USN-8084-1 curl vulnerabilities

Zhicheng Chen discovered that curl could incorrectly reuse the wrong connection for Negotiate-authenticated HTTP or HTTPS requests. This could result in the use of credentials from a different connection, contrary to expectations. CVE-2026-1965 It was discovered that curl incorrectly leaked OAuth...

ALPINE-CVE-2026-3784

curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP proxy. The proper behavior is to create or use a separate connection...

CVE-2026-3784

curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP proxy. The proper behavior is to create or use a separate connection...

CVE-2026-3805

When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory...

CVE-2026-3783

When an OAuth2 bearer token is used for an HTTPS 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 redirected to has information in the used .netrc file, with eithe...

ALPINE-CVE-2026-3805

When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory...

ALPINE-CVE-2026-3783

When an OAuth2 bearer token is used for an HTTPS 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 redirected to has information in the used .netrc file, with eithe...

DEBIAN-CVE-2026-3784

curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP proxy. The proper behavior is to create or use a separate connection...

DEBIAN-CVE-2026-3783

When an OAuth2 bearer token is used for an HTTPS 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 redirected to has information in the used .netrc file, with eithe...

CVE-2026-1965

libcurl can in some circumstances reuse the wrong connection when asked to do an Negotiate-authenticated HTTP or HTTPS request. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of...

CVE-2026-3805 use after free in SMB connection reuse

When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory...

CVE-2026-3805

When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory...

CVE-2026-3805

CVE-2026-3805 describes a heap-use-after-free in curl’s SMB connection reuse. During needle-based connection reuse, curl sets req->path to point inside the connection-owned smbc->share memory. When the needle is freed, smbc->share is freed as well, but req->path on the easy handle rem...

CVE-2026-3805 use after free in SMB connection reuse

When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory...

CVE-2026-3805

When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory...

CVE-2026-3805 use after free in SMB connection reuse

When doing a second SMB request to the same host again, curl would wrongly use a data pointer pointing into already freed memory...