CVE-2025-49506: Apache Portable Runtime Utility: apr_password_validate() vulnerable to timing attack

Published Aug 6, 2026
·
Updated

Apache Portable Runtime Utility: aprpasswordvalidate() vulnerable to timing attack

Other sources

APR-util versions 1.6.3 (and earlier) function aprpasswordvalidate() was not constant-time with regards to hashes or passwords comparisons, potentially leaking their content via a side channel timing attack particularly on platforms without crypt() such as  Windows, BeOS, NetWare, or Android.

Users are recommended to upgrade to version 1.6.4, which fixes this issue.

MITRE

Affected Software

3 affected componentsFixes available
Apache apr-util<=1.6.3
Apache apr-util>=1.2.0<1.6.4
Microsoft azl3 apr-util 1.6.3-2<1.6.3-3
1.6.3-3

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 1.6.3-3
  2. Upgrade

    Upgrade apr-util to a version that resolves this vulnerability.

    Fixed in 1.6.4Patch CVE-2025-49506

Event History

Aug 6, 2026
CVE Published
via MITRE·02:33 PM
Data Sourced
via MITRE·02:33 PM
DescriptionWeakness
Data Sourced
via NVD·03:16 PM
DescriptionSeverityWeaknessAffected Software
Aug 9, 2026
Data Sourced
via Microsoft·08:02 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·08:02 AM
Affected Software
Updated
via Microsoft·08:02 AM
DescriptionSeverity

Frequently Asked Questions

1

What is the severity of CVE-2025-49506?

CVE-2025-49506 is rated as a risk of 37, indicating a moderate severity level.

2

How do I fix CVE-2025-49506?

To fix CVE-2025-49506, upgrade to Apache APR-util version 1.6.4 or later where the timing attack vulnerability in apr_password_validate() is addressed.

3

Which versions are affected by CVE-2025-49506?

CVE-2025-49506 impacts Apache APR-util versions 1.6.3 and earlier.

4

What is the main issue related to CVE-2025-49506?

The main issue with CVE-2025-49506 is that the apr_password_validate() function is not constant-time, which can lead to timing attacks that expose password hashes.

5

On which platforms is CVE-2025-49506 particularly concerning?

CVE-2025-49506 is particularly concerning on platforms without crypt(), such as Windows, BeOS, NetWare, or Android.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203