How severe is CVE-2026-39820?

CVE-2026-39820 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-2026-39820 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-39820?

CVE-2026-39820 affects Golang Go. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-39820?

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-2026-39820 have an EU (EUVD) identifier?

Yes. CVE-2026-39820 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28423.

When was CVE-2026-39820 published?

CVE-2026-39820 was published on 2026-05-07 and last updated on 2026-07-08.

CVE-2026-39820

CVE-2026-39820 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-770.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-28423
Weakness: CWE-770
Affected product: Golang Go
Published: 2026-05-07
Last modified: 2026-07-08

Description

Well-crafted inputs reaching ParseAddress, ParseAddressList, and ParseDate were able to trigger excessive CPU exhaustion and memory allocations.

Frequently asked questions

What is CVE-2026-39820?: Well-crafted inputs reaching ParseAddress, ParseAddressList, and ParseDate were able to trigger excessive CPU exhaustion and memory allocations.
How severe is CVE-2026-39820?: CVE-2026-39820 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-2026-39820 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-39820?: CVE-2026-39820 affects Golang Go. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-39820?: 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-2026-39820 have an EU (EUVD) identifier?: Yes. CVE-2026-39820 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28423.
When was CVE-2026-39820 published?: CVE-2026-39820 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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