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

CSIRTS triage

What

The encoding/asn1 package lacks maximum recursion depth enforcement, allowing denial of service.

Who is affected

Go applications that parse untrusted ASN.1 data using the encoding/asn1 package.

Urgency

High severity (CVSS 7.5); unbounded recursion can exhaust stack and crash the application; patch promptly.

Action

Update Go to a patched version that enforces recursion depth limits in encoding/asn1.

AI-assisted analysis generated from the source advisory — verify against the original.

Details

Source

Microsoft Security Response Center (INTL · vendor-psirt · site)

Severity

high — CVSS 7.5

Published

2026-08-11

Exploitation

Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-33818

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

• Low exploitation riskCVE-2026-338180.46% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 39% of all EPSS-scored CVEs.

Referenced CVEs

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

• high[NEW] [high] Golang Go: Multiple vulnerabilitiescert-bund
• highCVE-2026-33818: Enforce a recursion limit in Unmarshal to prevent stack exhaustion when parsing deeply-nested,…nvd

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