What is CVE-2026-27143?

CVE-2026-27143 is a critical-severity vulnerability in Golang Go, classified under CWE-190: INTEGER OVERFLOW OR WRAPAROUND. CVSS score: 9.8/10. Published 2026-04-08.

How severe is CVE-2026-27143?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Golang Go

CVE-2026-27143

Arithmetic over induction variables in loops were not correctly checked for underflow or overflow. As a result, the compiler would allow for invalid indexing to occur at runtime, potentially leading to memory corruption.

Published 2026-04-08 · last modified 2026-07-25.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.007 (49.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.007 · change: +0.001

Affected products

Golang Go
Go Toolchain Cmd/compile — versions 0, 1.26.0-0

References

go.dev/cl/763765 (Patch)
go.dev/issue/78333 (Issue Tracking)
groups.google.com/g/golang-announce/c/0uYbvbPZRWU (Mailing List, Release Notes)
pkg.go.dev/vuln/GO-2026-4868 (Vendor Advisory)

Frequently asked questions

What is CVE-2026-27143?: CVE-2026-27143 is a critical-severity vulnerability in Golang Go, classified under CWE-190: INTEGER OVERFLOW OR WRAPAROUND. CVSS score: 9.8/10. Published 2026-04-08.
How severe is CVE-2026-27143?: Critical severity. CVSS v3 base score is 9.8 out of 10.