CVE-2025-9640: samba Use of Uninitialized Resource
CVSS: 4.3v3.1MediumDeferred
AliasesALPINE-CVE-2025-9640UBUNTU-CVE-2025-9640DEBIAN-CVE-2025-9640DLA-4384-1
Published 15-10-2025Last modified 01-09-2026
Vulnerability summary
CVE-2025-9640 is a medium (CVSS 4.3) Use of Uninitialized Resource vulnerability in samba. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 38.7% of scored vulnerabilities.
CVSS score
4.3/10
010
Medium · v3.1 (CVE.org)EPSS score
0.46%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 13 · Related 12Timeline
- 15-10-2025PublishedVulnerability first disclosed.
- 01-09-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
5 scores · 5 sources · 1 versionMedium 4.3Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:NSourcesAll 5 agree
- OSV · AlpineEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- OSV · UbuntuEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- OSV · DebianEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- NVDNIST4.3MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.46%
Chance of exploitation in the next 30 days
Percentile
39%
Versus all other CVEs
30-day change
0.00 pp
From 0.46% on 19-09-2026
19-09-202619-10-2026
EPSS score0.46%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Alpine1 product
- samba< 4.21.9-r0
Debian1 product
- samba< 2:4.17.12+dfsg-0+deb12u3 | < 2:4.22.6+dfsg-0+deb13u1 | < 2:4.23.2+dfsg-1 | < 2:4.13.13+dfsg-1~deb11u7
Ubuntu1 product
- samba< 2:4.3.11+dfsg-0ubuntu0.14.04.20+esm15 | < 2:4.3.11+dfsg-0ubuntu0.16.04.34+esm4 | < 2:4.7.6+dfsg~ubuntu-0ubuntu2.29+esm3 | < 2:4.15.13+dfsg-0ubuntu0.20.04.8+esm1 | < 2:4.15.13+dfsg-0ubuntu1.10 | < 2:4.19.5+dfsg-4ubuntu9.4 | < 2:4.22.3+dfsg-4ubuntu2.1
3 vendors · 3 products
