CVE-2026-33818 Enforce maximum recursion depth in encoding/asn1
Attackers can cause stack exhaustion and denial of service by parsing deeply nested ASN.1 structures in the Go standard library.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-33818?
CVE-2026-33818 is a high-severity denial of service vulnerability in Go standard library encoding/asn1, published on 13 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Enforce a recursion limit in Unmarshal to prevent stack exhaustion when parsing deeply-nested, recursive structures.
Weakness: CWE-400
Which versions are affected by CVE-2026-33818?
2 open source packages ship an affected version, including golang and stdlib.
| Package | Affected | Fixed in |
|---|---|---|
golang Bitnami | All versions | 1.25.13, 1.26.6, 1.27.0 |
stdlib Go | All versions | 1.25.13, 1.26.6, 1.27.0-rc.3 |
How do I fix CVE-2026-33818?
Upgrade golang to a fixed version for your release line: 1.25.13, 1.26.6 or 1.27.0.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-33818 being exploited?
There is no known exploitation of CVE-2026-33818 in the wild and no public exploit code.
Sources
Also known as AZL-96653, AZL-96686, BELL-CVE-2026-33818, BIT-golang-2026-33818, CLEANSTART-2026-DH56111, CLEANSTART-2026-DM50191 and 2153 more.