How severe is CVE-2025-9640?

CVE-2025-9640 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2025-9640 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-9640?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-9640 have an EU (EUVD) identifier?

Yes. CVE-2025-9640 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-34611.

When was CVE-2025-9640 published?

CVE-2025-9640 was published on 2025-10-15 and last updated on 2026-06-30.

CVE-2025-9640

CVE-2025-9640 is a medium-severity vulnerability with a CVSS 3.x base score of 4.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-908.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-34611
Weakness: CWE-908
Published: 2025-10-15
Last modified: 2026-06-30

Description

A flaw was found in Samba, in the vfs_streams_xattr module, where uninitialized heap memory could be written into alternate data streams. This allows an authenticated user to read residual memory content that may include sensitive data, resulting in an information disclosure vulnerability.

Frequently asked questions

What is CVE-2025-9640?: A flaw was found in Samba, in the vfs_streams_xattr module, where uninitialized heap memory could be written into alternate data streams. This allows an authenticated user to read residual memory content that may include sensitive data, resulting in an information disclosure vulnerability.
How severe is CVE-2025-9640?: CVE-2025-9640 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2025-9640 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-9640?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-9640 have an EU (EUVD) identifier?: Yes. CVE-2025-9640 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-34611.
When was CVE-2025-9640 published?: CVE-2025-9640 was published on 2025-10-15 and last updated on 2026-06-30.

References

Other CWE-908 (Use of Uninitialized Resource) vulnerabilities

CVE-2025-1942 — Critical (CVSS 9.8): When String.toUpperCase() caused a string to get longer it was possible for uninitialized memory to be incorporated…
CVE-2024-47540 — Critical (CVSS 9.8): GStreamer is a library for constructing graphs of media-handling components. An uninitialized stack variable…
CVE-2024-32611 — Critical (CVSS 9.8): HDF5 Library through 1.14.3 may use an uninitialized value in H5A__attr_release_table in H5Aint.c.
CVE-2023-24941 — Critical (CVSS 9.8): Windows Network File System Remote Code Execution Vulnerability
CVE-2022-26437 — Critical (CVSS 9.8): In httpclient, there is a possible out of bounds write due to uninitialized data. This could lead to remote escalation…
CVE-2021-45703 — Critical (CVSS 9.8): An issue was discovered in the tectonic_xdv crate before 0.1.12 for Rust. XdvParser::<T>::process may read from…

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