NVD / CVE Program· CNA Linux

CVE-2025-38501: ksmbd: limit repeated connections from clients with the same IP

Noroxi assessment

Priority: Monitor (action score 31/100)

Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
Probability of exploitation in the next 30 days: 2.1% (FIRST EPSS); higher than 82.1% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: Linux Linux 6073afe64510c302b7a0683a01e32c012eff715d, 7e5d91d3e6c62a9755b36f29c35288f06c3cd86b, cb092fc3a62972a4aa47c9fe356c2c6a01cd840b; azl3 kernel 6.6.96.2-2 on Azure Linux 3.0 6.6.104.2-1.

Low priority for now. Upgrade to Linux Linux 6073afe64510c302b7a0683a01e32c012eff715d, 7e5d91d3e6c62a9755b36f29c35288f06c3cd86b, cb092fc3a62972a4aa47c9fe356c2c6a01cd840b; azl3 kernel 6.6.96.2-2 on Azure Linux 3.0 6.6.104.2-1 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: limit repeated connections from clients with the same IP Repeated connections from clients with the same IP address may exhaust the max connections and prevent other normal client connections. This patch limit repeated connections from clients with the same IP.

HighCVSS 7.5 · v3.1—Proof of concept Fix available

BDU:2025-15555

Published: Aug 16, 2025
Updated: Aug 5, 2026
EPSS: 2.1% · 82th percentile
CWE: CWE-400

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 1 / 30 · 2.1%

CISA SSVC decision

Exploitation: proof of concept
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: 7.5
CNA · Linux: 7.5; agree

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
Proof of concept exists, no weaponized module
A fix has been released

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

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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.

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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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel
debian	debian linux	cpe:2.3:o:debian:debian_linux

Affected versions

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

debian debian linux11.0
linux linux kernel5.15 and later · before 6.1.148
linux linux kernel6.2 and later · before 6.6.102
linux linux kernel6.7 and later · before 6.12.42
linux linux kernel6.13 and later · before 6.15.10
linux linux kernel6.16 and later · before 6.16.1

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 cb092fc3a62972a4aa47c9fe356c2c6a01cd840baffected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before fa1c47af4ff641cf9197ecdb1f8240cbb30389c1affected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 7e5d91d3e6c62a9755b36f29c35288f06c3cd86baffected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before f1ce9258bcbce2491f9f71f7882b6eed0b33ec65affected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 6073afe64510c302b7a0683a01e32c012eff715daffected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before e6bb9193974059ddbb0ce7763fa3882bd60d4dc3affected · git
- before 5.15not affected · semver
- 6.1.148 and later · up to and including 6.1.*not affected · semver
- 6.6.102 and later · up to and including 6.6.*not affected · semver

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.148-1	6.1.148-1
Debian:13	linux	before 6.12.43-1	6.12.43-1
Debian:14	linux	before 6.16.3-1	6.16.3-1

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-2025-38499Aug 11, 2025 · clone_private_mnt(): make sure that caller has CAP_SYS_ADMIN in the right userns
22Monitor
← EarlierCVE-2025-38500Aug 12, 2025 · xfrm: interface: fix use-after-free after changing collect_md xfrm interface
31Monitor
Later →CVE-2025-38503Aug 16, 2025 · btrfs: fix assertion when building free space tree
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 / package	Fixed version	Source
Linux Linux	6073afe64510c302b7a0683a01e32c012eff715d	Vendor (CNA)
Linux Linux	7e5d91d3e6c62a9755b36f29c35288f06c3cd86b	Vendor (CNA)
Linux Linux	cb092fc3a62972a4aa47c9fe356c2c6a01cd840b	Vendor (CNA)
Linux Linux	e6bb9193974059ddbb0ce7763fa3882bd60d4dc3	Vendor (CNA)
Linux Linux	f1ce9258bcbce2491f9f71f7882b6eed0b33ec65	Vendor (CNA)
Linux Linux	fa1c47af4ff641cf9197ecdb1f8240cbb30389c1	Vendor (CNA)
azl3 kernel 6.6.96.2-2 on Azure Linux 3.0	6.6.104.2-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.148-1 · Debian:12	Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
Source	Kind	Date
Proof-of-concept repository on GitHub	stars:4	2025-09-15

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.

PublishedAug 16, 2025
First PoCSep 15, 2025+30 d
TodayOct 28, 2026+439 d

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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-2024-39462417 days apartclk: bcm: dvp: Assign ->num before accessing ->hws
39Monitor
CVE-2021-4440417 days apartx86/xen: Drop USERGS_SYSRET64 paravirt call
35Monitor
CVE-2026-46273291 days apartibmveth: Disable GSO for packets with small MSS
34Monitor
CVE-2021-47313452 days apartcpufreq: CPPC: Fix potential memleak in cppc_cpufreq_cpu_init
33Monitor
CVE-2024-38616423 days apartwifi: carl9170: re-fix fortified-memset warning
32Monitor
CVE-2021-47023535 days apartnet: marvell: prestera: fix port event handling on init
32Monitor

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

Anyone who can reach it over the internet can trigger it.
No account or password is required.
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: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

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

nvd-primary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}