How severe is CVE-2026-33811?

CVE-2026-33811 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-33811 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33811?

CVE-2026-33811 affects Golang Go. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33811?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-33811 have an EU (EUVD) identifier?

Yes. CVE-2026-33811 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28419.

When was CVE-2026-33811 published?

CVE-2026-33811 was published on 2026-05-07 and last updated on 2026-07-08.

CVE-2026-33811

CVE-2026-33811 is a high-severity vulnerability in Golang Go with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-415.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (53rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-28419
Weakness: CWE-415
Affected product: Golang Go
Published: 2026-05-07
Last modified: 2026-07-08

Description

When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash.

Frequently asked questions

What is CVE-2026-33811?: When using LookupCNAME with the cgo DNS resolver, a very long CNAME response can trigger a double-free of C memory and a crash.
How severe is CVE-2026-33811?: CVE-2026-33811 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-33811 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33811?: CVE-2026-33811 affects Golang Go. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33811?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-33811 have an EU (EUVD) identifier?: Yes. CVE-2026-33811 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28419.
When was CVE-2026-33811 published?: CVE-2026-33811 was published on 2026-05-07 and last updated on 2026-07-08.

References

Affected products (1)

cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*

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