Is CVE-2025-9640 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2025-9640 being exploited in the wild.

How severe is CVE-2025-9640?

Medium severity, with a CVSS score of 4.3, published 15 October 2025.

Which products and versions are affected?

Samba < 4.21.9, 4.22.0 < 4.22.5, 4.23.0 < 4.23.2.

Is there a fix for CVE-2025-9640?

A patch was published on 2026-05-26: Security releases 4.24.3, 4.23.8, and 4.22.10 made available Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2025-9640 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2025-9640?

Check whether you run Samba at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2025-9640: Samba uninitialized memory disclosure in vfs_streams_xattr

Q: Which products and versions are affected?

Samba < 4.21.9, 4.22.0 < 4.22.5, 4.23.0 < 4.23.2.

Q: Is there a fix for CVE-2025-9640?

A patch was published on 2026-05-26: Security releases 4.24.3, 4.23.8, and 4.22.10 made available Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

Q: How is CVE-2025-9640 attacked?

It is attacked over the network, in a software library.

Q: Am I affected by CVE-2025-9640?

Check whether you run Samba at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2025-9640 · Severity: medium · CVSS 4.3 · Published 2025-10-15

Samba, a widely used software suite for file and print sharing between Linux and Windows systems, contains a vulnerability in its handling of extended file attributes. An authenticated user could exploit this flaw to read sensitive information from the server's memory that they should not have access to. This could lead to the exposure of residual data from other system processes or user sessions.

Technologies: Samba. Vendors: Samba.

Quick answers

Is CVE-2025-9640 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2025-9640 being exploited in the wild.
How severe is CVE-2025-9640?: Medium severity, with a CVSS score of 4.3, published 15 October 2025.
Which products and versions are affected?: Samba < 4.21.9, 4.22.0 < 4.22.5, 4.23.0 < 4.23.2.
Is there a fix for CVE-2025-9640?: A patch was published on 2026-05-26: Security releases 4.24.3, 4.23.8, and 4.22.10 made available Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2025-9640 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2025-9640?: Check whether you run Samba at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A flaw was found in the Samba vfs_streams_xattr module (CWE-908). The vulnerability occurs when uninitialized heap memory is written into alternate data streams (ADS). An authenticated attacker with network access to a Samba share can exploit this to read residual memory content. This residual data may contain sensitive information from previous operations or other processes. The issue is addressed in Samba versions 4.21.9, 4.22.5, and 4.23.2.

Affected products

Samba Samba < 4.21.9, 4.22.0 < 4.22.5, 4.23.0 < 4.23.2

Timeline

2025-08-29: other: Initial bug report in Red Hat Bugzilla
2025-10-15: disclosed: Public disclosure of the vulnerability
2026-05-26: patched: Security releases 4.24.3, 4.23.8, and 4.22.10 made available

References

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