JLSEC-2026-406

A path traversal vulnerability exists in curl 8.0.0 SFTP implementation causes the tilde character to be wrongly replaced when used as a prefix in the first path element, in addition to its intended use as the first element to indicate a path relative to the user's home directory. Attackers can...

JLSEC-2026-389

The curl URL parser wrongly accepts percent-encoded URL separators like '/'when decoding the host name part of a URL, making it a different URL usingthe wrong host name when it is later retrieved.For example, a URL like http://example.com%2F127.0.0.1/, would be allowed bythe parser and get...

JLSEC-2026-405

A vulnerability in input validation exists in curl 8.0 during communication using the TELNET protocol may allow an attacker to pass on maliciously crafted user name and "telnet options" during server negotiation. The lack of proper input scrubbing allows an attacker to send content or perform...

JLSEC-2026-387

An information disclosure vulnerability exists in curl 7.65.0 to 7.82.0 are vulnerable that by using an IPv6 address that was in the connection pool but with a different zone id it could reuse a connection instead...

JLSEC-2026-403

A cleartext transmission of sensitive information vulnerability exists in curl v7.88.0 that could cause HSTS functionality to behave incorrectly when multiple URLs are requested in parallel. Using its HSTS support, curl can be instructed to use HTTPS instead of using an insecure clear-text HTTP...

JLSEC-2026-400

A vulnerability exists in curl 7.87.0 HSTS check that could be bypassed to trick it to keep using HTTP. Using its HSTS support, curl can be instructed to use HTTPS instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. However, the HSTS mechanism could be bypasse...

JLSEC-2026-408

A denial of service vulnerability exists in curl v8.1.0 in the way libcurl provides several different backends for resolving host names, selected at build time. If it is built to use the synchronous resolver, it allows name resolves to time-out slow operations using alarm and siglongjmp. When doi...

JLSEC-2026-420 When asked to use a `.netrc` file for credentials **and** to follow HTTP redirects, curl could leak...

When asked to use a .netrc file for credentials and to follow HTTP redirects, curl could leak the password used for the first host to the followed-to host under certain circumstances. This flaw only manifests itself if the netrc file has a default entry that omits both login and password. A rare...

JLSEC-2026-430 When doing SSH-based transfers using either SCP or SFTP, and setting the `known_hosts` file, libcurl...

When doing SSH-based transfers using either SCP or SFTP, and setting the knownhosts file, libcurl could still mistakenly accept connecting to hosts not present in the specified file if they were added as recognized in the libssh global knownhosts file...

JLSEC-2026-399

In curl before 7.86.0, the HSTS check could be bypassed to trick it into staying with HTTP. Using its HSTS support, curl can be instructed to use HTTPS directly instead of using an insecure cleartext HTTP step even when HTTP is provided in the URL. This mechanism could be bypassed if the host nam...

JLSEC-2026-386

An insufficiently protected credentials vulnerability exists in curl 4.9 to and include curl 7.82.0 are affected that could allow an attacker to extract credentials when follows HTTPS redirects is used with authentication could leak credentials to other services that exist on different protocols ...

JLSEC-2026-385

An improper authentication vulnerability exists in curl 7.33.0 to and including 7.82.0 which might allow reuse OAUTH2-authenticated connections without properly making sure that the connection was authenticated with the same credentials as set for this transfer. This affects SASL-enabled protocol...

JLSEC-2026-409

An improper certificate validation vulnerability exists in curl v8.1.0 in the way it supports matching of wildcard patterns when listed as "Subject Alternative Name" in TLS server certificates. curl can be built to use its own name matching function for TLS rather than one provided by a TLS...

JLSEC-2026-410

An information disclosure vulnerability exists in curl v8.1.0 when doing HTTPS transfers, libcurl might erroneously use the read callback CURLOPTREADFUNCTION to ask for data to send, even when the CURLOPTPOSTFIELDS option has been set, if the same handle previously wasused to issue a PUT request...

JLSEC-2026-388

A insufficiently protected credentials vulnerability in fixed in curl 7.83.0 might leak authentication or cookie header data on HTTP redirects to the same host but another port number...

JLSEC-2026-419 When curl is asked to use HSTS, the expiry time for a subdomain might overwrite a parent domain's...

When curl is asked to use HSTS, the expiry time for a subdomain might overwrite a parent domain's cache entry, making it end sooner or later than otherwise intended. This affects curl using applications that enable HSTS and use URLs with the insecure HTTP:// scheme and perform transfers with host...

JLSEC-2026-402

A cleartext transmission of sensitive information vulnerability exists in curl v7.88.0 that could cause HSTS functionality fail when multiple URLs are requested serially. Using its HSTS support, curl can be instructed to use HTTPS instead of usingan insecure clear-text HTTP step even when HTTP is...

JLSEC-2026-429 When doing TLS related transfers with reused easy or multi handles and altering the...

When doing TLS related transfers with reused easy or multi handles and altering the CURLSSLOPTNOPARTIALCHAIN option, libcurl could accidentally reuse a CA store cached in memory for which the partial chain option was reversed. Contrary to the user's wishes and expectations. This could make libcur...

JLSEC-2026-439 When doing a second SMB request to the same host again, curl would wrongly use a data pointer...

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

JLSEC-2026-426 When using `CURLOPT_PINNEDPUBLICKEY` option with libcurl or `--pinnedpubkey` with the curl tool,curl...

When using CURLOPTPINNEDPUBLICKEY option with libcurl or --pinnedpubkey with the curl tool,curl should check the public key of the server certificate to verify the peer. This check was skipped in a certain condition that would then make curl allow the connection without performing the proper chec...