Review reviewHigh

CVE-2026-39820

Go standard library net/mail, Logging Subsystem for Red Hat OpenShift 6.4, Red Hat Advanced Cluster Security 4.9

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

CVSS
7.5
EPSS
0.78%
52.5% percentile
CISA KEV
Not listed
Published
2026.05.08
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.78%
Technical severityCVSS 7.5

Vulnerability overview

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

Affected product and versions

Product
Go standard library net/mail, Logging Subsystem for Red Hat OpenShift 6.4, Red Hat Advanced Cluster Security 4.9
Affected versions
< 1.25.10, >= 1.26.0-0 < 1.26.3, >= 1.26.0 < 1.26.3
Fixed versions
1.25.10, 1.26.3

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Go standard library net/mail, Logging Subsystem for Red Hat OpenShift 6.4, Red Hat Advanced Cluster Security 4.9 and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
CWE-606, CWE-770