- Exploited
- No known exploitation
- Fix
- Fixed in 1.26.11, 1.27.4
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 1.26.11, 1.27.4.
- Published
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 10/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
The Go toolchain's cgo build step (cmd/go) can run arbitrary commands when a malicious package is built with GCC, because GCC reads untrusted spec files from linker search directories. Exploiting it requires a package that uses cgo with specific linker flags such as "-fopenmp", "-fopenacc", or "-fsanitize=" in its cgo LDFLAGS.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
When using GCC, building a malicious package that uses cgo could cause arbitrary command execution at link time via untrusted GCC spec files ("specs" or "*.spec"). When linking with "-fopenmp", "-fopenacc", or "-fsanitize=" in "#cgo LDFLAGS", GCC's built-in link spec evaluates "%:include(libgomp.spec)" or "%:include(libsanitizer.spec)" and searches for spec files in "-L" and sysroot directories (including subdirectories and multilib sibling directories such as "../lib64"), as well as the working directory when "-fopenmp" or "-fopenacc" is used or when "-fsanitize=" is combined with "-static" or "-static-lib*". The go command now rejects "-L", "-isysroot", and "-Wl,-syslibroot" directories (and the working and package directories when applicable) that contain GCC spec files, and disallows "@" and "-" prefixes in "-fsanitize=" compiler flag values.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure?/25Unknown. No advisory context yet
- Reach10/20Affects Go packages
- Severity?/10Unknown. No CVSS score or vendor rating
- No patch0/5No signal
What would change the score
- Would score about 65 if added to CISA KEV
- Would score about 60 if CISA's SSVC rates exploitation active
- Would score about 32 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 1.26.11, 1.27.4.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-97034 (Arbitrary command execution via GCC spec files in cgo linker search directories in cmd/go), using the cve.now data below. Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only. What cve.now has for CVE-2026-97034 (entry last updated 2026-11-11): Affected: - Go package cmd/go: fixed in 1.26.11; from 1.27.0-0, fixed in 1.27.4 - Go package toolchain: fixed in 1.26.11; from 1.27.0-0, fixed in 1.27.4 Fixed versions: 1.26.11, 1.27.4. Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory. CISA KEV: CVE-2026-97034 is not listed as of cve.now's last read. This KEV status is for CVE-2026-97034 only. If you also check another CVE, look up its own KEV status; never assume it from this one. How to check: - Packages (Go): find every lockfile in each project and run check_stack from the cve.now MCP server on each one. Compare the resolved versions, not the ranges a manifest declares, with the affected versions above. Include transitive dependencies. Verify against the linked advisories before concluding, and cite the date you read each one: - https://go.dev/cl/862147 - https://go.dev/issue/82576 - https://groups.google.com/g/golang-announce/c/iY8TY0wWgbM - https://pkg.go.dev/vuln/GO-2026-6857 Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing. Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action. Entry: https://cve.now/CVE-2026-97034 For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example get_vulnerability with id CVE-2026-97034.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- cmd/goGo
fixed in 1.26.11; From 1.27.0-0 · fixed in 1.27.4
fixed in 1.26.11; From 1.27.0-0 · fixed in 1.27.4
Evidence 6
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Other links · 4
- Link
- Link
- Link
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-97034
Is CVE-2026-97034 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-97034?
cmd/go (Go): before 1.26.11; from 1.27.0-0 before 1.27.4. toolchain (Go): before 1.26.11; from 1.27.0-0 before 1.27.4.Source: cve.now feed data
How do I fix CVE-2026-97034?
Upgrade to a fixed version: 1.26.11, 1.27.4.Source: cve.now feed data