Symlink following in Go cmd/go "go bug" temporary files
CVE-2026-39819 affects the Go toolchain's cmd/go component. The "go bug" command created two files with predictable names in the system temporary directory (for example, /tmp). Because those filenames were predictable and the command followed symlinks, an attacker with access to that temporary directory could pre-create a symbolic link at one of those paths and cause "go bug" to write to the symlink target instead of a safe temporary file. The Go project fixed this by changing "go bug" to use os.MkdirTemp to create a safe working directory for its temporary files.
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Impact, mitigation & remediation
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Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
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Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
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Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
2 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.
No news coverage yet. Advisories and community discussion only.
The version that knows your environment.
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Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.