Golang: stdlib: security update to 1.25.10stdlib: security update to 1.26.3

high Tenable Cloud Security Plugin ID 441497

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

- 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-2026-42501)

Solution

Update the stdlib library and its related packages to version 1.25.10 or later.

Plugin Details

Severity: High

ID: 441497

Version: Revision 1.6

Type: Local

Family: Golang

Published: 5/8/2026

Updated: 6/2/2026

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2026-42501

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 5/7/2026

Vulnerability Publication Date: 5/7/2026

Reference Information

CVE: CVE-2026-42501

Detections

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