CVE Intelligence

Golang vulnerabilities

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Published CVEs affecting Golang products: 76 record(s), with severity, exploitation and fixes.

Exploited only (KEV) →

CVE-2026-42505 Medium · 5.3 CWE-201 Jul 8, 2026
Invoking Encrypted Client Hello privacy leak in crypto/tls
Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.
CVE-2026-39822 High · 7.8 CWE-61 Jul 8, 2026
Root escape via symlink plus trailing slash in os
On Unix systems, opening a file in an os.Root improperly follows symlinks to locations outside of the Root when the final path component of the a path is a symbolic link and the path ends in /. For example, 'root.Open("symlink/")' will open "symlink" even when "symlink" is a symbolic link pointing outside of the root.
CVE-2026-46604 High · 7.5 CWE-787 Jun 26, 2026
Panic decoding image with out-of-bounds strip offset in x/image/tiff in golang.org/x/image
The TIFF decoder can panic when decoding an invalid image with an out-of-bounds strip offset.
CVE-2023-54365 High · 7.5 CWE-400 Jun 23, 2026
Traefik - Denial of Service via HTTP/2 Request Handling
Traefik before 2.10.5 and 3.0.0-beta4 is affected by a denial-of-service vulnerability in HTTP/2 request handling inherited from the Go standard library's HTTP/2 implementation (CVE-2023-44487 / CVE-2023-39325, the 'Rapid Reset' technique). A remote attacker can rapidly create and cancel HTTP/2 streams to exhaust server resources and cause service unavailability.
CVE-2026-42506 Medium · 6.1 CWE-79 May 22, 2026
Invoking incorrect handling of namespaced elements in foreign content in golang.org/x/net/html
Parsing arbitrary HTML which is then rendered using Render can result in an unexpected HTML tree. This can be leveraged to execute XSS attacks in applications that attempt to sanitize input HTML before rendering.
CVE-2026-42502 Medium · 6.1 CWE-1021 May 22, 2026
Invoking incorrect handling of HTML elements in foreign content in golang.org/x/net/html
Parsing arbitrary HTML which is then rendered using Render can result in an unexpected HTML tree. This can be leveraged to execute XSS attacks in applications that attempt to sanitize input HTML before rendering.
CVE-2026-39821 Critical · 9.6 CWE-1289 May 22, 2026
Invoking failure to reject ASCII-only Punycode-encoded labels in golang.org/x/net/idna
The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-only label. For example, ToUnicode("xn--example-.com") incorrectly returns the name "example.com" rather than an error. This behavior can lead to privilege escalation in programs using the idna package. For example, a program which performs privilege checks on the ASCII hostname may reject "example.com" but permit "xn--example-.com". If that program subsequently converts the ASCII hostname to Unicode, it will inadvertently permits access to the Unicode name "example.com".
CVE-2026-27136 Medium · 6.1 CWE-1021 May 22, 2026
Invoking duplicate attributes can cause XSS in golang.org/x/net/html
Parsing arbitrary HTML which is then rendered using Render can result in an unexpected HTML tree. This can be leveraged to execute XSS attacks in applications that attempt to sanitize input HTML before rendering.
CVE-2026-25681 Medium · 6.1 CWE-1021 May 22, 2026
Invoking incorrect handling of character references in DOCTYPE nodes in golang.org/x/net/html
Parsing arbitrary HTML which is then rendered using Render can result in an unexpected HTML tree. This can be leveraged to execute XSS attacks in applications that attempt to sanitize input HTML before rendering.
CVE-2026-25680 Medium · 6.5 CWE-400 May 22, 2026
Invoking denial of service when parsing arbitrary HTML in golang.org/x/net/html
Parsing arbitrary HTML can consume excessive CPU time, possibly leading to denial of service.
CVE-2026-46598 Medium · 5.3 CWE-129 May 22, 2026
Invoking pathological inputs can lead to client panic in golang.org/x/crypto/ssh/agent
For certain crafted inputs, a 'ed25519.PrivateKey' was created by casting malformed wire bytes, leading to a panic when used.
CVE-2026-46597 High · 7.5 CWE-704 May 22, 2026
Invoking byte arithmetic causes underflow and panic in golang.org/x/crypto/ssh
An incorrectly placed cast from bytes to int allowed for server-side panic in the AES-GCM packet decoder for well-crafted inputs.
CVE-2026-46595 Critical · 10.0 CWE-863 May 22, 2026
Invoking VerifiedPublicKeyCallback permissions skip enforcement in golang.org/x/crypto/ssh
Previously, CVE-2024-45337 fixed an authorization bypass for misused ssh server configurations; if any other type of callback is passed other than public key, then the source-address validation would be skipped.
CVE-2026-42508 Critical · 9.1 CWE-295 May 22, 2026
Invoking auth bypass via unenforced @revoked status in golang.org/x/crypto/ssh/knownhosts
Previously, a revoked 'SignatureKey' belonging to a CA was not correctly checked for revocation. Now, both the 'key' and 'key.SignatureKey' are checked for @revoked.
CVE-2026-39835 Medium · 5.3 CWE-295 May 22, 2026
Invoking server panic during CheckHostKey/Authenticate in golang.org/x/crypto/ssh
SSH servers which use CertChecker as a public key callback without setting IsUserAuthority or IsHostAuthority could be caused to panic by a client presenting a certificate. CertChecker now returns an error instead of panicking when these callbacks are nil.
CVE-2026-39834 Critical · 9.1 CWE-190 May 22, 2026
Invoking infinite loop on large channel writes in golang.org/x/crypto/ssh
When writing data larger than 4GB in a single Write call on an SSH channel, an integer overflow in the internal payload size calculation caused the write loop to spin indefinitely, sending empty packets without making progress. The size comparison now uses int64 to prevent truncation.
CVE-2026-39833 Critical · 9.1 CWE-862 May 22, 2026
Invoking key constraints not enforced in golang.org/x/crypto/ssh/agent
The in-memory keyring returned by NewKeyring() silently accepted keys with the ConfirmBeforeUse constraint but never enforced it. The key would sign without any confirmation prompt, with no indication to the caller that the constraint was not in effect. NewKeyring() now returns an error when unsupported constraints are requested.
CVE-2026-39832 Critical · 9.1 CWE-502 May 22, 2026
Invoking agent constraints dropped when forwarding keys in golang.org/x/crypto/ssh/agent
When adding a key to a remote agent constraint extensions such as restrict-destination-v00@openssh.com were not serialized in the request. Destination restrictions were silently stripped when forwarding keys, allowing unrestricted use of the key on the remote host. The client now serializes all constraint extensions. Additionally, the in-memory keyring returned by NewKeyring() now rejects keys with unsupported constraint extensions instead of silently ignoring them.
CVE-2026-39831 Critical · 9.1 CWE-862 May 22, 2026
Invoking bypass of FIDO/U2F security keys physical interaction in golang.org/x/crypto/ssh
The Verify() method for FIDO/U2F security key types (sk-ecdsa-sha2-nistp256@openssh.com, sk-ssh-ed25519@openssh.com) did not check the User Presence flag. Signatures generated without physical touch were accepted, allowing unattended use of a hardware security key. To restore the previous behavior, return a "no-touch-required" extension in Permissions.Extensions from PublicKeyCallback.
CVE-2026-39830 Critical · 9.1 CWE-119 May 22, 2026
Invoking client can cause server deadlock on unexpected responses in golang.org/x/crypto/ssh
A malicious SSH peer could send unsolicited global request responses to fill an internal buffer, blocking the connection's read loop. The blocked goroutine could not be released by calling Close(), resulting in a resource leak per connection. Unsolicited global responses are now discarded.
CVE-2026-39829 High · 7.5 CWE-347 May 22, 2026
Invoking pathological RSA/DSA parameters may cause DoS in golang.org/x/crypto/ssh
The RSA and DSA public key parsers did not enforce size limits on key parameters. A crafted public key with an excessively large modulus or DSA parameter could cause several minutes of CPU consumption during signature verification. This could be triggered by unauthenticated clients during public key authentication. RSA moduli are now limited to 8192 bits, and DSA parameters are validated per FIPS 186-2.
CVE-2026-39828 Medium · 6.3 CWE-295 May 22, 2026
Invoking bypass of certificate restrictions in golang.org/x/crypto/ssh
When an SSH server authentication callback returned PartialSuccessError with non-nil Permissions, those permissions were silently discarded, potentially dropping certificate restrictions such as force-command after a second factor succeeded. Returning non-nil Permissions with PartialSuccessError now results in a connection error.
CVE-2026-39827 Medium · 6.5 CWE-924 May 22, 2026
Invoking memory leak when rejecting channels can lead to DoS in golang.org/x/crypto/ssh
An authenticated SSH client that repeatedly opened channels which were rejected by the server caused unbounded memory growth, eventually crashing the server process and affecting all connected users. Rejected channels are now properly removed from the connection's internal state and released for garbage collection.
CVE-2026-42501 High · 7.5 CWE-347 May 7, 2026
Malicious module proxy can bypass checksum database in cmd/go
A malicious module proxy can exploit a flaw in the go command's validation of module checksums to bypass checksum database validation. This vulnerability affects any user using an untrusted module proxy (GOMODPROXY) or checksum database (GOSUMDB). A malicious module proxy can serve altered versions of the Go toolchain. When selecting a different version of the Go toolchain than the currently installed toolchain (due to the GOTOOLCHAIN environment variable, or a go.work or go.mod with a toolchain line), the go command will download and execute a toolchain provided by the module proxy. A malicious module proxy can bypass checksum database validation for this downloaded toolchain. Since this vulnerability affects the security of toolchain downloads, setting GOTOOLCHAIN to a fixed version is not sufficient. You must upgrade your base Go toolchain. The go tool always validates the hash of a toolchain before executing it, so fixed versions will refuse to execute any cached, altered versions of the toolchain. The go tool trusts go.sum files to contain accurate hashes of the current module's dependencies. A malicious proxy exploiting this vulnerability to serve an altered module will have caused an incorrect hash to be recorded in the go.sum. Users who have configured a non-trusted GOPROXY can determine if they have been affected by running "rm go.sum ; go mod tidy ; go mod verify", which will revalidate all dependencies of the current module. The specific flaw in more detail: The go command consults the checksum database to validate downloaded modules, when a module is not listed in the go.sum file. It verifies that the module hash reported by the checksum database matches the hash of the downloaded module. If, however, the checksum database returns a successful response that contains no entry for the module, the go command incorrectly permitted validation to succeed. A module proxy may mirror or proxy the checksum database, in which case the go command will not connect to the checksum database directly. Checksums reported by the checksum database are cryptographically signed, so a malicious proxy cannot alter the reported checksum for a module. However, a proxy which returns an empty checksum response, or a checksum response for an unrelated module, could cause the go command to proceed as if a downloaded module has been validated.
CVE-2026-42499 High · 7.5 CWE-1046 May 7, 2026
Quadratic string concatenation in consumePhrase in net/mail
Pathological inputs could cause DoS through consumePhrase when parsing an email address according to RFC 5322.