From 9db98021278ce511e75435bf23610f52880605ae Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Pawe=C5=82=20Gronowski?= Date: Thu, 8 Oct 2026 20:19:46 +0200 Subject: [PATCH] Update to go1.26.9 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This release includes 15 security fixes following the security policy: - net/http: HTTP/2 server crash due to HPACK encoder race HTTP/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 header table size to crash the server. Fix this issue by not applying SETTINGS_HEADER_TABLE_SIZE immediately. Instead, buffer any SETTINGS_HEADER_TABLE_SIZE received, and only apply the new value prior to the next time the server writes a frame. Thanks to RyotaK (https://ryotak.net) of GMO Flatt Security Inc. for reporting this issue. This is CVE-2026-97032 and Go issue https://go.dev/issue/81867. - net/http: HTTP/2 server memory exhaustion due to Trailer headers When "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. This exploit is not applicable for HTTP/1 servers, which do not support multiplexing a large number of requests over one TCP connection, and whose Server.MaxHeaderBytes are calculated differently. Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits are now applied towards the trailer fields declared in "Trailer" headers. Thanks to RyotaK (https://ryotak.net) of GMO Flatt Security Inc. for reporting this issue. This is CVE-2026-78659 and Go issue https://go.dev/issue/81857. - crypto/tls: reject malformed ECH outer extension references Multiple 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. This is CVE-2026-97031 and Go issue https://go.dev/issue/81855. - cmd/go: checksum bypass for golang.org/fips140 Previously, a user operating inside of a malicious Go project that defines a bogus golang.org/fips140 and operates a malicious GOMODPROXY the user chooses to connect to can serve an arbitrary module in its place. We now unpack the trusted ziphash for the bundled golang.org/fips140 module and construct its entry in the GOMODCACHE such that it can be verified by the toolchain. This is CVE-2026-94444 and Go issue https://go.dev/issue/81833. - cmd/go: checksum database bypass for golang.org/toolchain Previously, a user operating inside of a malicious Go project that defines a bogus golang.org/toolchain go.sum entry and operates a malicious GOMODPROXY the user chooses to use can bypass the intended checksum. We now ensure that golang.org/toolchain always goes to the network for the canonical checksum. This is CVE-2026-94447 and Go issue https://go.dev/issue/81834. - html/template: reset context tracking on consecutive template expressions When 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. This is CVE-2026-94448 and Go issue https://go.dev/issue/81821. - html/template: recognize yield as regexp preceder keyword A 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. This is CVE-2026-97030 and Go issue https://go.dev/issue/81823. - net/textproto, mime/multipart: memory limit bypass when parsing MIME headers Parsing a multipart form could bypass memory limits and read an arbitrarily long line into memory when the remaining limit at the start of a part was less than 400 bytes. Multipart form memory limits are now properly enforced in this situation. Thanks to Jakub Ciolek (https://ciolek.dev) for reporting this issue. This is CVE-2026-94440 and Go issue https://go.dev/issue/81741. - net/http: HTTP/1 client connection desynchronization after CONNECT rejection When 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 desynchronized and causing the next caller that reuses it to read the response to the injected request. In reverse proxies (including httputil.ReverseProxy) that forward CONNECT requests through a shared Transport, this can lead to cross-user response poisoning. The HTTP/1 transport now closes a connection after sending a CONNECT request, regardless of the response status. In addition, ReverseProxy now rejects incoming CONNECT requests with a 405 Method Not Allowed response. ReverseProxy has never handled CONNECT requests in a useful fashion (it does not convert the connection into a bidirectional tunnel), so we do not expect this change to negatively affect any current users. Thanks to Xclow3n (Rajat Raghav) for reporting this issue. This is CVE-2026-56866 and Go issue https://go.dev/issue/81740. - net/http: HTTP/1 server connection desynchronization after 2xx CONNECT response When an HTTP server handler sent a 2xx response to an HTTP/1 CONNECT request and returned without hijacking the connection, the server improperly continued 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 connection to be tunneled and the server considers it to be HTTP. The HTTP/1 server now always closes a connection after responding to a CONNECT request, regardless of the response status. Thanks to Jakub Ciolek (https://ciolek.dev) for reporting this issue. This is CVE-2026-94439 and Go issue https://go.dev/issue/81744. - net/http: excessive CPU consumption from repeated initial window changes A malicious HTTP/2 peer could 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. The HTTP/2 client and server now efficiently handle changes to the initial window size (O(1) rather than O(number of streams)). Thanks to Jakub Ciolek (https://ciolek.dev) for reporting this issue. This is CVE-2026-78669 and Go issue https://go.dev/issue/81742. - net/http: HTTP/2 transport accepts malformed framing-related headers Historically, 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. We now delete malformed framing-related headers when received by our HTTP/2 transport, so they will not be forwarded to a potentially vulnerable HTTP/1 client. Thanks to TJ Barton for reporting this issue. This is CVE-2026-78660 and Go issue https://go.dev/issue/81115. - os: Root.Mkdir(All) can follow junctions out of the root on Windows On Windows, when the target of Root.Mkdir or Root.MkdirAll was a junction pointing to an empty location, the operation would create a directory at the junction target even when that target was 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). Root.Mkdir and Root.MkdirAll now correctly avoid resolving junctions. Thanks to Daniele Ballarini for reporting this issue. This is CVE-2026-56857 and Go issue https://go.dev/issue/81739. - net/http: lack of limit on size of parsed Range headers When parsing a Range header containing a large number of small ranges, FileServer(FS), ServeContent, and ServeFile(FS) could consume an excessive amount of CPU. These functions now ignore Range headers containing more than 200 ranges. The limit is controlled by the new httpservecontentmaxranges= GODEBUG setting. Setting GODEBUG=httpservecontentmaxranges=0 disables the limit. Thanks to Jakub Ciolek (https://ciolek.dev) for reporting this issue. This is CVE-2026-78667 and Go issue https://go.dev/issue/81858. - net/http: double flow control refund on HTTP/2 server streams The HTTP/2 server could 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 could 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. The HTTP/2 server now waits to refund connection-level flow control for reset streams until after the request handler is complete. Thanks to Ali Sherif (https://www.linkedin.com/in/ali-sherif-13812b276/) for reporting this issue. This is CVE-2026-78663 and Go issue https://go.dev/issue/81743. release notes: https://go.dev/doc/devel/release#go1.26.9 Signed-off-by: Paweł Gronowski --- .github/workflows/codeql.yml | 2 +- .github/workflows/test.yml | 2 +- .github/workflows/validate.yml | 2 +- .golangci.yml | 2 +- Dockerfile | 2 +- dockerfiles/Dockerfile.dev | 2 +- dockerfiles/Dockerfile.lint | 2 +- dockerfiles/Dockerfile.vendor | 2 +- 8 files changed, 8 insertions(+), 8 deletions(-) diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml index 48e32d6ef1..ead4a4f0f2 100644 --- a/.github/workflows/codeql.yml +++ b/.github/workflows/codeql.yml @@ -64,7 +64,7 @@ jobs: name: Update Go uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0 with: - go-version: "1.26.8" + go-version: "1.26.9" cache: false - name: Initialize CodeQL diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml index 459abb3163..6b6a5ea564 100644 --- a/.github/workflows/test.yml +++ b/.github/workflows/test.yml @@ -68,7 +68,7 @@ jobs: name: Set up Go uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0 with: - go-version: "1.26.8" + go-version: "1.26.9" cache: false - name: Test diff --git a/.github/workflows/validate.yml b/.github/workflows/validate.yml index 25507e1aab..1396c8d7b0 100644 --- a/.github/workflows/validate.yml +++ b/.github/workflows/validate.yml @@ -101,7 +101,7 @@ jobs: name: Set up Go uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0 with: - go-version: "1.26.8" + go-version: "1.26.9" cache: false - name: Run gocompat check diff --git a/.golangci.yml b/.golangci.yml index ad5a06f1d8..ac80456651 100644 --- a/.golangci.yml +++ b/.golangci.yml @@ -5,7 +5,7 @@ run: # which causes it to fallback to go1.17 semantics. # # TODO(thaJeztah): update "usetesting" settings to enable go1.24 features once our minimum version is go1.24 - go: "1.26.8" + go: "1.26.9" timeout: 5m diff --git a/Dockerfile b/Dockerfile index 02d1fc7d7d..59f519dcbe 100644 --- a/Dockerfile +++ b/Dockerfile @@ -8,7 +8,7 @@ ARG BASE_VARIANT=alpine ARG ALPINE_VERSION=3.23 ARG BASE_DEBIAN_DISTRO=bookworm -ARG GO_VERSION=1.26.8 +ARG GO_VERSION=1.26.9 # XX_VERSION specifies the version of the xx utility to use. # It must be a valid tag in the docker.io/tonistiigi/xx image repository. diff --git a/dockerfiles/Dockerfile.dev b/dockerfiles/Dockerfile.dev index 7f02956252..c1a7d04c27 100644 --- a/dockerfiles/Dockerfile.dev +++ b/dockerfiles/Dockerfile.dev @@ -1,6 +1,6 @@ # syntax=docker/dockerfile:1 -ARG GO_VERSION=1.26.8 +ARG GO_VERSION=1.26.9 # ALPINE_VERSION sets the version of the alpine base image to use, including for the golang image. # It must be a supported tag in the docker.io/library/alpine image repository diff --git a/dockerfiles/Dockerfile.lint b/dockerfiles/Dockerfile.lint index b0404ab8b8..e6acf6f718 100644 --- a/dockerfiles/Dockerfile.lint +++ b/dockerfiles/Dockerfile.lint @@ -1,6 +1,6 @@ # syntax=docker/dockerfile:1 -ARG GO_VERSION=1.26.8 +ARG GO_VERSION=1.26.9 # ALPINE_VERSION sets the version of the alpine base image to use, including for the golang image. # It must be a supported tag in the docker.io/library/alpine image repository diff --git a/dockerfiles/Dockerfile.vendor b/dockerfiles/Dockerfile.vendor index d781ef9830..442e88286e 100644 --- a/dockerfiles/Dockerfile.vendor +++ b/dockerfiles/Dockerfile.vendor @@ -1,6 +1,6 @@ # syntax=docker/dockerfile:1 -ARG GO_VERSION=1.26.8 +ARG GO_VERSION=1.26.9 # ALPINE_VERSION sets the version of the alpine base image to use, including for the golang image. # It must be a supported tag in the docker.io/library/alpine image repository