Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2025-21748: ksmbd: fix integer overflows on 32 bit systems

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.60% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 760568c1f62ea874e8fb492f9cfa4f47b4b8391e, 82f59d64e6297f270311b16b5dcf65be406d1ea3, aab98e2dbd648510f8f51b83fbf4721206ccae45; azl3 kernel 6.6.64.2-9 on Azure Linux 3.0 6.6.78.1-3; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.78.1-3.
  • Severity is disputed: the assigning authority (CNA) scores it 9.8, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 760568c1f62ea874e8fb492f9cfa4f47b4b8391e, 82f59d64e6297f270311b16b5dcf65be406d1ea3, aab98e2dbd648510f8f51b83fbf4721206ccae45; azl3 kernel 6.6.64.2-9 on Azure Linux 3.0 6.6.78.1-3; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.78.1-3 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix integer overflows on 32 bit systems On 32bit systems the addition operations in ipc_msg_alloc() can potentially overflow leading to memory corruption. Add bounds checking using KSMBD_IPC_MAX_PAYLOAD to avoid overflow.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Feb 26, 2025
Updated
Aug 5, 2026
EPSS
0.6% · 48th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.6%

CNA vs NVD score

NVD
5.5
CNA · Linux
9.8
4.3 point gap

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-21748

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

Your free account also gets you

Running WordPress? Scan your site free with WP Lens

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel5.15 and later · before 6.1.129
  • linux linux kernel6.2 and later · before 6.6.78
  • linux linux kernel6.7 and later · before 6.12.14
  • linux linux kernel6.13 and later · before 6.13.3

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 5.15affected
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before f3b9fb2764591d792d160f375851013665a9e820affected · git
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 760568c1f62ea874e8fb492f9cfa4f47b4b8391eaffected · git
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 82f59d64e6297f270311b16b5dcf65be406d1ea3affected · git
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before b4b902737746c490258de5cb55cab39e79927a67affected · git
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before ecb9947fa7c99a77b04d43404c6988a0d326e4a0affected · git
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before aab98e2dbd648510f8f51b83fbf4721206ccae45affected · git
    • before 5.15not affected · semver
    • 5.15.179 and later · up to and including 5.15.*not affected · semver
    • 6.1.129 and later · up to and including 6.1.*not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.129-16.1.129-1
Debian:13linuxbefore 6.12.15-16.12.15-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2025-21746Feb 26, 2025 · Input: synaptics - fix crash when enabling pass-through port
    18Monitor
  • ← EarlierCVE-2025-21747Feb 26, 2025 · drm/ast: astdp: Fix timeout for enabling video signal
    22Monitor
  • Later →CVE-2025-21749Feb 26, 2025 · net: rose: lock the socket in rose_bind()
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux760568c1f62ea874e8fb492f9cfa4f47b4b8391eVendor (CNA)
Linux Linux82f59d64e6297f270311b16b5dcf65be406d1ea3Vendor (CNA)
Linux Linuxaab98e2dbd648510f8f51b83fbf4721206ccae45Vendor (CNA)
Linux Linuxb4b902737746c490258de5cb55cab39e79927a67Vendor (CNA)
Linux Linuxecb9947fa7c99a77b04d43404c6988a0d326e4a0Vendor (CNA)
Linux Linuxf3b9fb2764591d792d160f375851013665a9e820Vendor (CNA)
azl3 kernel 6.6.64.2-9 on Azure Linux 3.06.6.78.1-3 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.78.1-3 on Azure Linux 3.06.6.78.1-3 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.179.1-1 on CBL Mariner 2.05.15.179.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.182.1-1 on CBL Mariner 2.0CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.182.1-1 on CBL-Mariner 2.05.15.179.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.129-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-31633422 days apartrxrpc: Fix integer overflow in rxgk_verify_response()
    39Monitor
  • CVE-2026-31649422 days apartnet: stmmac: fix integer underflow in chain mode
    39Monitor
  • CVE-2026-31659422 days apartbatman-adv: reject oversized global TT response buffers
    39Monitor
  • CVE-2026-43341436 days apartnet/ipv6: ioam6: prevent schema length wraparound in trace fill
    39Monitor
  • CVE-2026-46039455 days apartrxgk: Fix potential integer overflow in length check
    39Monitor
  • CVE-2026-46325468 days apartRDMA/rxe: Fix iova-to-va conversion for MR page sizes != PAGE_SIZE
    39Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-190 · Integer Overflow or Wraparound

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records