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Fencer Intel
no cvss —

CVE-2026-97033 json

Unexpected code execution via --sysroot, -target, -isysroot, -Wl,-syslibroot, and -x cgo flags in cmd/go

published yesterday modified yesterday also EUVD-2026-123112 , GO-2026-6858

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 16%
public exploits
0
none known

Summary

Building a malicious package that uses cgo could cause arbitrary code execution at build time through several compiler and linker flags permitted in "#cgo" directives. Specifically, "--sysroot" in GCC and Clang relocates compiler subprograms, spec files, and CRT startup objects to an attacker-controlled directory; "-target" in Clang falls back to executing target helper tools from the current working directory when not found in PATH; "-isysroot" and "-Wl,-syslibroot" can pass a regular file on disk to GNU ld.bfd, which interprets it as a positional linker script; and "-x" permitted specifying arbitrary compiler input languages beyond those supported by cgo. "--sysroot" and "-target" are now disallowed in "#cgo" flags, "-isysroot" and "-Wl,-syslibroot" are verified not to point to regular files, and "-x" is restricted to the C, C++, Objective-C, and assembler languages supported by cgo.

Patch / fix

  • go toolchain 1.26.11, 1.27.4
  • Go toolchain cmd/go 1.26.11, 1.27.4

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Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 16% of all scored CVEs (FIRST EPSS, 2026-11-11).

Affected packages

ecosystem package affected fixed in
go toolchain
<1.26.11
>=1.27.0-0, <1.27.4
1.26.11
1.27.4

Affected products

  • Go toolchain cmd/go

Classification

Weakness
  • CWE-77 Improper Neutralization of Special Elements used in a Command

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.