What’s Vulnerable › Vulnerabilities

CVE-2026-33818: Enforce maximum recursion depth in encoding/asn1

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-13 · updated 2026-11-01
• Weakness: CWE-400

Description

Enforce a recursion limit in Unmarshal to prevent stack exhaustion when parsing deeply-nested, recursive structures.

Affected products

• Go Stdlib: before 1.25.13; from 1.26.0-0 before 1.26.6; from 1.27.0-0 before 1.27.0-rc.3 — fixed in 1.25.13, 1.26.6, 1.27.0-rc.3
• Go standard library encoding/asn1: before 1.25.13; from 1.26.0-0 before 1.26.6; from 1.27.0-0 before 1.27.0-rc.3 — fixed in 1.25.13, 1.26.6, 1.27.0-rc.3

How to fix

Upgrade to a fixed version: Go Stdlib 1.25.13, 1.26.6, 1.27.0-rc.3; Go standard library encoding/asn1 1.25.13, 1.26.6, 1.27.0-rc.3. Check the vendor advisory for mitigations.

References

• https://go.dev/cl/814980
• https://go.dev/issue/80405
• https://groups.google.com/g/golang-announce/c/94pEornpRlI
• https://pkg.go.dev/vuln/GO-2026-5972

Get alerted when CVE-2026-33818 or the next vulnerability affects your stack