CVE-2026-398207.5HighCWE-407

CVE-2026-39820: Quadratic string concatentation in consumeComment in net/mail

Go standard library · net/mail

Vendor fix available · Affected: Go standard library net/mail · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.8%probability of exploitation in the next 30 days

56th percentile

050100

Higher than 56% of scored CVEs

7.5HighCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

Go standard library · net/mailbefore 1.25.10; from 1.26.0-0 before 1.26.3

On the Atlas

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Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Inefficient Algorithmic Complexity · Denial of Service
Vendor: Go standard library
Published: May 2026
Band: Unlikely (under 1%), May 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-39820 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.

References

28 more references are in the CVE record.