CVE-2026-39820

Aliases:GO-2026-4986BIT-golang-2026-39820
Advisory lineage Upstream: 0 Downstream: 10
Analyzed
Published: 07 May 2026, 19:41
Last modified:22 Jul 2026, 12:08

Vulnerability Summary

Overall Risk (default)
medium
30/100
CVSS Score
7.5 HIGH
v3.1 (cve.org)
EPSS Score
0.78% LOW
1% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

07 May 2026, 19:41
Published
Vulnerability first disclosed
22 Jul 2026, 12:08
Last Modified
Vulnerability information updated

Description

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

CVSS Metrics

  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.78%• Percentile: 52%

Techniques & Countermeasures

  • CWE-770•Allocation of Resources Without Limits or Throttling

    The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.

  • CWE-606•Unchecked Input for Loop Condition

    The product does not properly check inputs that are used for loop conditions, potentially leading to a denial of service or other consequences because of excessive looping.

Affected Systems

  • go standard library•net/mail

    < 1.25.10 | ≥ 1.26.0-0, < 1.26.3

  • golang•go

    < 1.25.10 | ≥ 1.26.0, < 1.26.3

  • Go•stdlib

    ≥ 1.26.0-0, < 1.26.3

References (27)