Go standard library

Exploited now

None of this vendor's CVEs are on CISA's known-exploited list.

Recent

• 6.8MediumOct 21, 2026Go standard library crypto/x509 Crypto / certificateCVE-2026-111943On most platforms, Go uses the given system root certificates. However, in some narrower cases, the system trust stores may not be updated without further action. To defend against the narrower set of cases that may remain affected, a denylist was added in crypto/x509 to return an error when calling
• 7.5HighOct 8, 2026Go standard library net/httpCVE-2026-97032HTTP/2 servers could end up crashing due to inadvertently modifying its HPACK encoder concurrently. This happens because the server modifies the HPACK encoder from two goroutines without synchronization: one uses the encoder to encode a HEADERS frame as part of a response sent to a client and the other modifies the encoder's table size when handling a SETTINGS frame containing SETTINGS_HEADER_TABLE_SIZE that a client sends. A malicious client can repeatedly send a request while changing the head
• 7.5HighOct 8, 2026Go standard library crypto/tlsCVE-2026-97031Multiple ECH outer extension references are not permitted under RFC 9849; previously, a client could send a well-crafted packet that could trigger memory exhaustion in the server process by specifying multiple references. We now reject these as malformed and curb the memory amplification vector as a result.
• 6.1MediumOct 8, 2026Go standard library html/template XSSCVE-2026-97030A trusted template author may have previously written a valid template wherein the use of the 'yield' keyword would not be correctly escaped. We now ensure that valid keyword uses are escaped and non-keyword uses are not escaped.
• 6.1MediumOct 8, 2026Go standard library html/template XSSCVE-2026-94448When a JavaScript template literal contains consecutive expressions, the context tracking state was not properly reset upon entering a new expression. We now ensure that template-literal expression entries correctly reset context variables so all subsequent regular expression literals are accurately recognized and escaped.
• 7.5HighOct 8, 2026Go standard library net/textproto Denial of serviceCVE-2026-94440Parsing a multipart form can bypass memory limits and read an arbitrarily long line into memory when the remaining limit at the start of a part is less than 400 bytes.
• 7.5HighOct 8, 2026Go standard library net/httpCVE-2026-94439When an HTTP server handler sends a 2xx response to an HTTP/1 CONNECT request and returns without hijacking the connection, the server improperly continues to read and serve requests from the connection. Since a 2xx response to an HTTP/1 CONNECT converts the connection into a tunnel, the server should not treat the connection as continuing to contain HTTP. The impact of this misbehavior is mostly limited to potential request smuggling, where an intermediate proxy considers the data on the connec
• 7.5HighOct 8, 2026Go standard library net/httpCVE-2026-78669A malicious HTTP/2 peer can cause excessive CPU consumption in the client or server by opening a large number of streams and then sending many small SETTINGS frames containing SETTINGS_INITIAL_WINDOW_SIZE values.
• 7.5HighOct 8, 2026Go standard library net/http Denial of serviceCVE-2026-78667When parsing a Range header containing a large number of small ranges, FileServer(FS), ServeContent, and ServeFile(FS) can consume an excessive amount of CPU.
• 9.1CriticalOct 8, 2026Go standard library net/httpCVE-2026-78663The HTTP/2 server can refund connection-level flow control twice for the same data: Once when a client resets a stream (refunding data for any sent-but-unread portion of the stream), and again when a request handler reads the buffered data. A malicious client can exploit this to bypass the configured connection-level flow control limit (MaxReceiveBufferPerConnection). Total buffered data is still limited by the concurrent stream limit and stream-level flow control.
• 7.5HighOct 8, 2026Go standard library net/httpCVE-2026-78660Historically, we have been rather lax about malformed framing-related headers in our HTTP/2 implementation, as they cannot interfere with HTTP/2 framing. However, this makes it possible for our HTTP/2 implementation to forward responses containing such headers to an HTTP/1 client when acting as a reverse proxy. If the HTTP/1 client also does not behave strictly enough, this can result in response smuggling.
• 7.5HighOct 8, 2026Go standard library net/httpCVE-2026-78659When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicious client can exploit this by sending a "Trailer" header that declares a large number of fields, causing the server to allocate a disproportionate amount of memory while bypassing Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits.
• 7.5HighOct 8, 2026Go standard library net/httpCVE-2026-56866When http.Transport sends an HTTP/1 CONNECT request with a non-empty Request.Body, it writes the body directly to the connection without framing after the request headers. If the server rejects the CONNECT request with a non-2xx keep-alive response, Transport returns the connection to the idle pool. Because CONNECT requests do not have a request body, the server may interpret the trailing body bytes as a subsequent pipelined HTTP/1.1 request on the connection, leaving the pooled connection desyn
• 9.8CriticalOct 8, 2026Go standard library osCVE-2026-56857On Windows, when the target of Root.Mkdir or Root.MkdirAll is a junction pointing to an empty location, the operation can create a directory at the junction target even when that target is located outside the root. This only applies to operations where the last path component is a junction (path/to/junction, but not path/junction/target).

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Top products

• net/http8 CVEs in the last year, 1 critical
• html/template2 CVEs in the last year
• os1 CVE in the last year, 1 critical
• net/textproto1 CVE in the last year
• crypto/x5091 CVE in the last year
• crypto/tls1 CVE in the last year

Advisories

Official advisories from the last 90 days that name this vendor's CVEs.

• AWS · Oct 25, 2026CVE-2026-111943: eMudhra intermediate CA key recovery in AWS trust bundlesCVE-2026-111943
• Google Kubernetes Engine · Oct 23, 2026GCP-2026-071CVE-2026-111943