Review reviewHigh

CVE-2026-43964

Postfix Postfix, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8

Postfix before 3.8.16, 3.9 before 3.9.10, and 3.10 before 3.10.9 sometimes allows a buffer over-read and process crash via an enhanced status code that lacks text after the third number.

CVSS
7.5
EPSS
0.41%
34.2% percentile
CISA KEV
Not listed
Published
2026.05.05
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.41%
Technical severityCVSS 7.5

Vulnerability overview

Postfix before 3.8.16, 3.9 before 3.9.10, and 3.10 before 3.10.9 sometimes allows a buffer over-read and process crash via an enhanced status code that lacks text after the third number.

Affected product and versions

Product
Postfix Postfix, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8
Affected versions
>= 2.3 < 3.8.16, >= 3.9 < 3.9.10, >= 3.10 < 3.10.9, < 3.8.16, >= 3.9.0 < 3.9.10, >= 3.10.0 < 3.10.9
Fixed versions
3.8.16, 3.9.10, 3.10.9

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Postfix Postfix, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8 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-193