Critical

Go cmd/compile bounds-check elimination memory corruption

IdentifiersCVE-2026-27143CWE-119

CVE-2026-27143 is a vulnerability in the Go compiler (cmd/compile) bound-check elimination logic. When optimizing loops, the compiler could incorrectly prove that slice or array accesses indexed by an induction variable were always in bounds. If that mutated induction variable could overflow or underflow relative to the loop condition, the optimization could remove necessary bounds checks anyway, allowing invalid indexing at runtime. This breaks Go's memory-safety guarantees for affected programs written in otherwise safe Go code and can result in out-of-bounds memory access and memory corruption.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation can cause out-of-bounds access beyond the original slice or array, leading to memory corruption. Reported consequences include breaking memory safety in safe Go programs, potential control-flow hijacking, and in at least one reported case the possibility of executing injected instructions. The practical impact depends on the compiled program containing a triggerable loop/indexing pattern that the vulnerable compiler misoptimizes.

Mitigation

If you can’t patch tonight, do this now.

If immediate upgrade is not possible, reduce exposure by rebuilding affected binaries with a fixed Go toolchain as soon as available. As a temporary risk-reduction measure, avoid code patterns where loop induction variables used for slice or array indexing can wrap, especially narrow integer types or arithmetic that may overflow/underflow relative to loop termination conditions. No complete mitigation equivalent to patching is provided in the content.

Remediation

Patch, then assume compromise.

Upgrade to a fixed Go release. The provided content states that Go 1.26.2 and Go 1.25.9 include the fix for CVE-2026-27143. The remediation changes cmd/compile so that mutated induction variables that may overflow or underflow with respect to their loop conditions are not used for bounds-check elimination.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

EXPOSURE SURFACE

Affected products & vendors

Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.

VendorProductType

GolangGoapplication

GolangGolangapplication

Rocky LinuxDelveapplication

Rocky LinuxGolangapplication

Rocky LinuxModule.Delveapplication

Rocky LinuxModule.Golangapplication

Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.

ACTIVITY FEED

Recent activity

15 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

15 SOURCESView more in app

go dev blogNews

Mar 27, 2026

cmd/compile: possible memory corruption after bound check elimination · Issue #78333 · golang/go

A Go compiler bounds check elimination flaw where mutated induction variables could be incorrectly proven in-bounds; if the indexing variable overflowed or underflowed, this could permit access beyond the original slice or array bounds.

What this page doesn’t show

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Exposure mapping

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Threat actor evidence

Every observed campaign linking this CVE to a named adversary.

Associated malware

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity11