Threat Intelligence Database

A malicious GOPROXY was previously capable of forging up to two sumdb tiles that allow for a requested module to bypass the GOSUMDB check and persist attacker-controlled module content to a local Go module cache. This attack allows for a malicious GOPROXY to serve malicious module content that cannot be detected by evaluating the transparency log. All tiles are now correctly verified against their parents. In order to determine if you have been affected: rm -r go.sum go.work.sum vendor/ && go mod tidy

A malicious GOSUMDB was capable of serving arbitrary module content not contained within the transparency log. This attack allows for a coordinating GOPROXY and GOSUMDB to serve a client malicious module content that cannot be detected by evaluating the transparency log. In order to determine if you have been affected: rm -r go.sum go.work.sum vendor/ && go mod tidy

CVE-2026-39819 is a medium severity vulnerability in the Go toolchain's cmd/go component. The 'go bug' command creates temporary files with predictable names in the system temporary directory. This allows an attacker with access to that directory to create symbolic links with those names, potentially causing the command to overwrite unintended files. No official patch or remediation is currently available, and no known exploits have been reported.

CVE-2026-39817 is a medium-severity path traversal vulnerability in the Go toolchain's cmd/go component, specifically affecting the 'go tool pack' subcommand. This flaw allows a malicious archive to write files to arbitrary filesystem locations due to improper sanitization of output filenames when extracting archives. It affects Go versions up to 1.26.0-0. There is currently no official patch or remediation guidance available, and no known exploits have been reported in the wild.

CVE-2026-42501 is a high-severity vulnerability in the Go toolchain's cmd/go module handling that allows a malicious module proxy to bypass checksum database validation due to improper verification of cryptographic signatures. This flaw enables acceptance of empty or unrelated checksum responses as valid, potentially leading to execution of altered Go toolchain versions or modules when using untrusted GOPROXY or GOSUMDB configurations. No official patch or remediation is currently available. Users are advised to upgrade their Go toolchain once a fix is released and can detect potential compromise by regenerating and verifying go.sum files. No known exploits have been reported in the wild at this time.

CVE-2026-27144 is a high-severity vulnerability in the Go toolchain's cmd/compile component. The issue arises because the compiler fails to correctly unwrap pointers during memory move operations due to a no-op interface conversion. This flaw can cause the compiler to incorrectly determine non-overlapping memory moves, potentially leading to memory corruption at runtime. The vulnerability affects Go versions up to 1.26.0-0. There is no vendor-provided patch or official remediation guidance available at this time, and no known exploits have been reported in the wild.

SWIG file names containing 'cgo' and well-crafted payloads could lead to code smuggling and arbitrary code execution at build time due to trust layer bypass.

Arithmetic over induction variables in loops were not correctly checked for underflow or overflow. As a result, the compiler would allow for invalid indexing to occur at runtime, potentially leading to memory corruption.

On Linux, if the target of Root.Chmod is replaced with a symlink while the chmod operation is in progress, Chmod can operate on the target of the symlink, even when the target lies outside the root. The Linux fchmodat syscall silently ignores the AT_SYMLINK_NOFOLLOW flag, which Root.Chmod uses to avoid symlink traversal. Root.Chmod checks its target before acting and returns an error if the target is a symlink lying outside the root, so the impact is limited to cases where the target is replaced with a symlink between the check and operation.

When verifying a certificate chain which contains a certificate containing multiple email address constraints which share common local portions but different domain portions, these constraints will not be properly applied, and only the last constraint will be considered.