CVE-2025-39795 | block: avoid possible overflow for chunk_sectors check in blk_stack_limits()

In the Linux kernel, the following vulnerability has been resolved: block: avoid possible overflow for chunk_sectors check in blk_stack_limits() In blk_stack_limits(), we check that the t->chunk_sectors value is a multiple of the t->physical_block_size value. However, by finding the chunk_sectors value in bytes, we may overflow the unsigned int which holds chunk_sectors, so change the check to be based on sectors.

Published: 2025-09-12 Last update: 2026-05-12 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2025-39795 is rated Low Risk (23.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-39795

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-01-17 0.06% 0.02% -0.04%
2 2026-01-12 0.02% 0.06% +0.04%
3 2025-09-13 0.02%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-39795

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.8 3.6 [email protected]

Weakness enumeration for CVE-2025-39795

GitHub Security Advisory for CVE-2025-39795

GHSA-x2v6-jx2x-c364 · Severity: medium — In the Linux kernel, the following vulnerability has been resolved: block: avoid possible...

OS Trackers for CVE-2025-39795

vendor priority summary link
debian not yet assigned CVE-2025-39795 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. https://security-tracker.debian.org/tracker/CVE-2025-39795
redhat low https://access.redhat.com/security/cve/CVE-2025-39795
suse medium CVE-2025-39795 severity moderate: SUSE including 110 source package names (13.2-9.1:libsqlite3-0-3.49.1-1.1, 2.1.3-6.31:libsqlite3-0-3.49.1-1.1, …), 367 product×package rows across 62 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (62 product lines)): Fixed 165, Known Not Affected 95, Will Not Fix 82, First Fixed 25. https://www.suse.com/security/cve/CVE-2025-39795/
ubuntu medium CVE-2025-39795 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, ignored 180, released 150, needed 48, not-affected 16, needs-triage 2, pending 1. https://ubuntu.com/security/CVE-2025-39795

Affected software / configurations for CVE-2025-39795

Vendor Product Version Raw CPE
linux linux_kernel >= 5.10, < 5.10.241 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.11, < 5.15.190 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16, < 6.1.149 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.103 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.12.43 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.13, < 6.15.11 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.16, < 6.16.2 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*

References for CVE-2025-39795

URL Tags
https://git.kernel.org/stable/c/14beeef4aafecc8a41de534e31fb5be94739392f Patch
https://git.kernel.org/stable/c/31f2f080898e50cbf2bae62d35f9f2a997547b38 Patch
https://git.kernel.org/stable/c/3b9d69f0e68aa6b0acd9791c45d445154a8c66e9 Patch
https://git.kernel.org/stable/c/418751910044649baa2b424ea31cce3fc4dcc253 Patch
https://git.kernel.org/stable/c/448dfecc7ff807822ecd47a5c052acedca7d09e8 Patch
https://git.kernel.org/stable/c/46aa80ef49594ed7de685ecbc673b291e9a2c159 Patch
https://git.kernel.org/stable/c/5e276e6ff9aacf8901b9c3265c3cdd2568c9fff2 Patch
https://git.kernel.org/stable/c/8b3ce085b52e674290cbfdd07034e7653ffbe4dc Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Third Party Advisory
https://cert-portal.siemens.com/productcert/html/ssa-032379.html
https://cert-portal.siemens.com/productcert/html/ssa-082556.html
cvelogic Threat Intelligence