239 matches found
CURL-CVE-2015-3153 sensitive HTTP server headers also sent to proxies
libcurl provides applications a way to set custom HTTP headers to be sent to the server by using CURLOPTHTTPHEADER. A similar option is available for the curl command-line tool with the '--header' option. When the connection passes through an HTTP proxy the same set of headers is sent to the prox...
CURL-CVE-2015-3145 cookie parser out of boundary memory access
libcurl supports HTTP "cookies" as documented in RFC 6265. Together with each individual cookie there are several different properties, but for this vulnerability we focus on the associated "path" element. It tells information about for which path on a given host the cookie is valid. The internal...
CURL-CVE-2014-0139 IP address wildcard certificate validation
libcurl incorrectly validates wildcard SSL certificates containing literal IP addresses. RFC 2818 covers the requirements for matching Common Names CNs and subjectAltNames in order to establish valid SSL connections. It first discusses CNs that are for hostnames, and the rules for wildcards in th...
CURL-CVE-2026-107928 info leak uploading over WebSockets with GnuTLS
When curl is built with GnuTLS, a malicious WebSocket server can make curl send memory past its send buffer. This is due to an out of bounds read following when gnutlsrecordsend returns a number of bytes sent greater than the number of bytes it was given to send. GnuTLS does that after a blocked...
CURL-CVE-2026-87861 cross-origin reuse of a Negotiate connection
When using ambient user credentials, an HTTP request directed to one origin may be dispatched over a connection previously authenticated via Negotiate for a different origin, leaving the request's intended credentials unused...
CURL-CVE-2026-92386 server-set cookie aborts cookie jar load
When writing a long cookie name and value to a Netscape cookie jar, a remote HTTP server can make curl write a record that exceeds its line-length parsing limit. Consequently, any subsequent curl invocation reading from that same cookie jar using --cookie silently aborts parsing prematurely upon...
CURL-CVE-2026-94266 password leak in CURLINFO_EFFECTIVE_URL
libcurl could accidentally return a URL for curleasygetinfo's CURLINFOEFFECTIVEURL option containing credentials, even though neither the URL provided to libcurl nor the redirected URL did...
CURL-CVE-2026-87864 IMAP APPEND plus CRLF conversion command injection
Enabling CURLOPTCRLF causes curl to advertise the raw input byte count in the IMAP APPEND N literal while transmitting line-ending expanded data. The server reads only $N$ bytes for the payload, causing the remaining overflow bytes to be interpreted and executed as pipelined IMAP commands within...
CURL-CVE-2026-92387 never-ending loop via server response omission
By permanently omitting the final control-response line, a malicious FTP, IMAP, POP3, or SMTP server can exploit libcurl and completely bypass its configured transfer timeout mechanism, indefinitely blocking all concurrent transfers bound to the same multi-handle...
CURL-CVE-2026-1965 bad reuse of HTTP Negotiate connection
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...
CURL-CVE-2025-14819 OpenSSL partial chain store policy bypass
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...
CURL-CVE-2025-14017 broken TLS options for threaded LDAPS
When doing multi-threaded LDAPS transfers LDAP over TLS with libcurl, changing TLS options in one thread would inadvertently change them globally and therefore possibly also affect other concurrently setup transfers. Disabling certificate verification for a specific transfer could unintentionally...
CURL-CVE-2025-10966 missing SFTP host verification with wolfSSH
curl's code for managing SSH connections when SFTP was done using the wolfSSH powered backend was flawed and missed host verification mechanisms. This prevents curl from detecting MITM attackers and more...
CURL-CVE-2025-4947 QUIC certificate check skip with wolfSSL
libcurl accidentally skips the certificate verification for QUIC connections when connecting to a host specified as an IP address in the URL. Therefore, it does not detect impostors or man-in-the-middle attacks...
CURL-CVE-2024-9681 HSTS subdomain overwrites parent cache entry
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...
CURL-CVE-2022-27779 cookie for trailing dot TLD
libcurl wrongly allows HTTP cookies to be set for Top Level Domains TLDs if the hostname is provided with a trailing dot. curl can be told to receive and send cookies when communicating using HTTPS. curl's "cookie engine" can be built with or without Public Suffix List awareness. If PSL support n...
CURL-CVE-2022-22576 OAUTH2 bearer bypass in connection reuse
libcurl might 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 protocols: SMTPS, IMAPS, POP3S and LDAPS OpenLDAP only. libcurl maintains a pool of live connection...
CURL-CVE-2021-22946 Protocol downgrade required TLS bypassed
A user can tell curl to require a successful upgrade to TLS when speaking to an IMAP, POP3 or FTP server --ssl-reqd on the command line or CURLOPTUSESSL set to CURLUSESSLCONTROL or CURLUSESSLALL with libcurl. This requirement could be bypassed if the server would return a properly crafted but...
CURL-CVE-2018-16890 NTLM type-2 out-of-bounds buffer read
libcurl contains a heap buffer out-of-bounds read flaw. The function handling incoming NTLM type-2 messages lib/vauth/ntlm.c:ntlmdecodetype2target does not validate incoming data correctly and is subject to an integer overflow vulnerability. Using that overflow, a malicious or broken NTLM server...
CURL-CVE-2019-3822 NTLMv2 type-3 header stack buffer overflow
libcurl contains a stack based buffer overflow vulnerability. The function creating an outgoing NTLM type-3 header lib/vauth/ntlm.c:Curlauthcreatentlmtype3message, generates the request HTTP header contents based on previously received data. The check that exists to prevent the local buffer from...
CURL-CVE-2017-8816 NTLM buffer overflow via integer overflow
libcurl contains a buffer overrun flaw in the NTLM authentication code. The internal function Curlntlmcoremkntlmv2hash sums up the lengths of the username + password = SUM and multiplies the sum by two = SIZE to figure out how large storage to allocate from the heap. The SUM value is subsequently...
CURL-CVE-2016-8623 Use after free via shared cookies
libcurl explicitly allows users to share cookies between multiple easy handles that are concurrently employed by different threads. When cookies to be sent to a server are collected, the matching function collects all cookies to send and the cookie lock is released immediately afterwards. That...
CURL-CVE-2016-8625 IDNA 2003 makes curl use wrong host
When curl is built with libidn to handle International Domain Names IDNA, it translates them to puny code for DNS resolving using the IDNA 2003 standard, while IDNA 2008 is the modern and up-to-date IDNA standard. This misalignment causes problems with for example domains using the German ß...
CURL-CVE-2016-7167 curl escape and unescape integer overflows
The four libcurl functions curlescape, curleasyescape, curlunescape and curleasyunescape perform string URL percent escaping and unescaping. They accept custom string length inputs in signed integer arguments. The functions having names without "easy" being the deprecated versions of the others...
CURL-CVE-2016-7141 Incorrect reuse of client certificates
libcurl built on top of NSS Network Security Services incorrectly reused client certificates if a certificate from file was used for one TLS connection but no certificate set for a subsequent TLS connection. While the symptoms are similar to CVE-2016-5420 Reusing connection with wrong client cert...
CURL-CVE-2014-8151 Secure Transport certificate check bypass
libcurl stores TLS Session IDs in its associated Session ID cache when it connects to TLS servers. In subsequent connects it reuses the entry in the cache to resume the TLS connection faster than when doing a full TLS handshake. The actual implementation for the Session ID caching varies dependin...
CURL-CVE-2026-87863 HSTS response erases persisted entries
An authenticated HTTPS origin can supply an HSTS max-age value that the parser accepts, but time serialization later fails to process. On 64-bit systems, extreme max-age values compute an absolute expiry within standard time integer limits that exceeds calendar time structure bounds. During cache...
CURL-CVE-2026-94265 Authorization: Negotiate sent to foreign origin
When processing an HTTP redirect to a URL containing userinfo a username:password component, curl might erroneously retain and re-transmit the original host's HTTP Negotiate authentication state. Consequently, a malicious server can trigger a redirect containing arbitrary userinfo to force curl t...
CURL-CVE-2026-80229 OpenSSL provider use-after-free
When performing transfers via libcurl’s multi interface, pooled TLS connections can outlive their originating easy handles. In OpenSSL 3 provider configurations, libcurl attaches an allocated library context to the easy handle's state and passes it to OpenSSL without acquiring an ownership...
CURL-CVE-2021-22897 Schannel cipher selection surprise
libcurl lets applications specify which specific TLS ciphers to use in transfers, using the option called CURLOPTSSLCIPHERLIST. The cipher selection is used for the TLS negotiation when a transfer is done involving any of the TLS based transfer protocols libcurl supports, such as HTTPS, FTPS,...
CURL-CVE-2020-8286 Inferior OCSP verification
libcurl offers "OCSP stapling" via the CURLOPTSSLVERIFYSTATUS option. When set, libcurl verifies the OCSP response that a server responds with as part of the TLS handshake. It then aborts the TLS negotiation if something is wrong with the response. The same feature can be enabled with --cert-stat...
CURL-CVE-2019-5481 FTP-KRB double free
libcurl can be told to use kerberos over FTP to a server, as set with the CURLOPTKRBLEVEL option. During such kerberos FTP data transfer, the server sends data to curl in blocks with the 32-bit size of each block first and then that amount of data immediately following. A malicious or broken serv...
CURL-CVE-2018-1000121 LDAP NULL pointer dereference
curl might dereference a near-NULL address when getting an LDAP URL. The function ldapgetattributeber is called to get attributes, but it turns out that it can return LDAPSUCCESS and still return a NULL pointer in the result pointer when getting a particularly crafted response. This was a surpris...
CURL-CVE-2017-1000100 TFTP sends more than buffer size
When doing a TFTP transfer and curl/libcurl is given a URL that contains a long filename longer than about 515 bytes, the filename is truncated to fit within the buffer boundaries, but the buffer size is still wrongly updated to use the original length. This too large value is then used in the...
CURL-CVE-2017-7468 TLS session resumption client cert bypass (again)
libcurl would attempt to resume a TLS session even if the client certificate had changed. That is unacceptable since a server by specification is allowed to skip the client certificate check on resume, and may instead use the old identity which was established by the previous certificate or no...
CURL-CVE-2016-8620 glob parser write/read out of bounds
The curl tool's "globbing" feature allows a user to specify a numerical range through which curl iterates. It is typically specified as 1-5, specifying the first and the last numbers in the range. Or with a-z, using letters. 1. The curl code for parsing the second unsigned number did not check fo...
CURL-CVE-2016-5421 use of connection struct after free
libcurl is vulnerable to a use after free flaw. libcurl works with easy handles using the type 'CURL ' that are objects the application creates using curleasyinit. They are the handles that are all each associated with a single transfer at a time. libcurl also has an internal struct that represen...
CURL-CVE-2016-5420 Reusing connections with wrong client cert
libcurl did not consider client certificates when reusing TLS connections. libcurl supports reuse of established connections for subsequent requests. It does this by keeping a few previous connections "alive" in a connection pool so that a subsequent request that can use one of them instead of...
CURL-CVE-2015-3237 SMB send off unrelated memory contents
libcurl can get tricked by a malicious SMB server to send off data it did not intend to. In libcurl's state machine function handling the SMB protocol smbrequeststate, two length and offset values are extracted from data that has arrived over the network, and those values are subsequently used to...
CURL-CVE-2015-3148 Negotiate not treated as connection-oriented
libcurl keeps a pool of its last few connections around after use to facilitate easy, convenient and completely transparent connection reuse for applications. When doing HTTP requests Negotiate authenticated, the entire connection may become authenticated and not only the specific HTTP request...
CURL-CVE-2014-3613 cookie leak with IP address as domain
By not detecting and rejecting domain names for partial literal IP addresses properly when parsing received HTTP cookies, libcurl can be fooled to both sending cookies to wrong sites and into allowing arbitrary sites to set cookies for others. For this problem to trigger, the client application...
CURL-CVE-2026-86412 server-set cookie erases cookie jar
A remote HTTP server can set a cookie that curl accepts and writes to a Netscape cookie jar but cannot reload. On the next invocation using the same path for --cookie and --cookie-jar, curl fails before connecting, then the cleanup procedure replaces the jar with an empty file, deleting cookies f...
CURL-CVE-2026-80231 native CA store conn reuse
A 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 CURLSSLOPTNATIVECA than when the connection was created...
CURL-CVE-2022-27782 TLS and SSH connection too eager reuse
libcurl would reuse a previously created connection even when a TLS or SSH related option had been changed that should have prohibited reuse. libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. However, several TLS and...
CURL-CVE-2021-22947 STARTTLS protocol injection via MITM
When curl connects to an IMAP, POP3, SMTP or FTP server to exchange data securely using STARTTLS to upgrade the connection to TLS level, the server can still respond and send back multiple responses before the TLS upgrade. Such multiple pipelined responses are cached by curl. curl would then...
CURL-CVE-2020-8231 wrong connect-only connection
An application that performs multiple requests with libcurl's multi API and sets the CURLOPTCONNECTONLY option, might in rare circumstances experience that when subsequently using the setup connect-only transfer, libcurl picks and uses the wrong connection - and instead picks another one the...
CURL-CVE-2017-8817 FTP wildcard out of bounds read
libcurl contains a read out of bounds flaw in the FTP wildcard function. libcurl's FTP wildcard matching feature, which is enabled with the CURLOPTWILDCARDMATCH option can use a built-in wildcard function or a user provided one. The built-in wildcard function has a flaw that makes it not detect t...
CURL-CVE-2017-1000257 IMAP FETCH response out of bounds read
libcurl contains a buffer overrun flaw in the IMAP handler. An IMAP FETCH response line indicates the size of the returned data, in number of bytes. When that response says the data is zero bytes, libcurl would pass on that non-existing data with a pointer and the size zero to the deliver-data...
CURL-CVE-2017-1000254 FTP PWD response parser out of bounds read
libcurl may read outside of a heap allocated buffer when doing FTP. When libcurl connects to an FTP server and successfully logs in anonymous or not, it asks the server for the current directory with the PWD command. The server then responds with a 257 response containing the path, inside double...
CURL-CVE-2016-3739 TLS certificate check bypass with mbedTLS/PolarSSL
libcurl did not check the server certificate of TLS connections done to a host specified as an IP address, or when explicitly asked to use SSLv3. This flaw only exists when libcurl is built to use mbedTLS or PolarSSL as the TLS backend. The documentation for mbedTLS and PolarSSL wrongly says that...