Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2026-72350: netfilter: xt_u32: reject invalid shift counts

Noroxi assessment

Priority: Monitor (action score 31/100)

  • 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: 0.17% (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 00d034fe8230dfc5832fe011ff2d81c1a2cc7a29, 0a8b7a6d763775709c601f584e709ae48bcc000a, 64cdf7d30ac18e43df6c48004435febb965809a8.

Low priority for now. Upgrade to Linux Linux 00d034fe8230dfc5832fe011ff2d81c1a2cc7a29, 0a8b7a6d763775709c601f584e709ae48bcc000a, 64cdf7d30ac18e43df6c48004435febb965809a8 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: netfilter: xt_u32: reject invalid shift counts u32_match_it() executes rule-supplied shift operands on a 32-bit value. A malformed u32 rule can provide a shift count of 32 or more, triggering an undefined shift out-of-bounds during packet evaluation. Validate XT_U32_LEFTSH and XT_U32_RIGHTSH operands in u32_mt_checkentry() and reject malformed rules before they reach the packet path.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Aug 15, 2026
Updated
Oct 16, 2026
EPSS
0.1% · 7th percentile
CWE
—

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.8
NVD has not scored this yet; the score shown is the CNA’s.

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-2026-72350

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

  • 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
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.

—

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

    • 2.6.23affected
    • 1b50b8a371e90a5e110f466e4ac02cf6b5f681de and later · before ca7c92d9701249e6daf132087756a88cbf2bb2a3affected · git
    • 1b50b8a371e90a5e110f466e4ac02cf6b5f681de and later · before b33b44250d57ab0e5a1e2571b5285fb0d0a7f382affected · git
    • 1b50b8a371e90a5e110f466e4ac02cf6b5f681de and later · before 728f479dc0447ae7eaef87926ff49142e415a811affected · git
    • 1b50b8a371e90a5e110f466e4ac02cf6b5f681de and later · before 0a8b7a6d763775709c601f584e709ae48bcc000aaffected · git
    • 1b50b8a371e90a5e110f466e4ac02cf6b5f681de and later · before cce42014415cecd98aa49b3950e7b02ee7c81268affected · git
    • 1b50b8a371e90a5e110f466e4ac02cf6b5f681de and later · before a597a722fb71a534138c20359b655726622b5f17affected · git
    • 1b50b8a371e90a5e110f466e4ac02cf6b5f681de and later · before 00d034fe8230dfc5832fe011ff2d81c1a2cc7a29affected · git
    • 1b50b8a371e90a5e110f466e4ac02cf6b5f681de and later · before 64cdf7d30ac18e43df6c48004435febb965809a8affected · git
    • before 2.6.23not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.180-16.1.180-1
Debian:13linuxbefore 6.12.100-16.12.100-1
Debian:14linuxbefore 7.1.5-17.1.5-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-72348Aug 15, 2026 · netfilter: ip6tables: mark malformed IPv6 extension headers for hotdrop
    36Monitor
  • ← EarlierCVE-2026-72349Aug 15, 2026 · netfilter: xt_rateest: fix u64 truncation in xt_rateest_mt()
    0Monitor
  • Later →CVE-2026-72351Aug 15, 2026 · gue: validate REMCSUM private option length
    39Monitor

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 Linux00d034fe8230dfc5832fe011ff2d81c1a2cc7a29Vendor (CNA)
Linux Linux0a8b7a6d763775709c601f584e709ae48bcc000aVendor (CNA)
Linux Linux64cdf7d30ac18e43df6c48004435febb965809a8Vendor (CNA)
Linux Linux728f479dc0447ae7eaef87926ff49142e415a811Vendor (CNA)
Linux Linuxa597a722fb71a534138c20359b655726622b5f17Vendor (CNA)
Linux Linuxb33b44250d57ab0e5a1e2571b5285fb0d0a7f382Vendor (CNA)
Linux Linuxca7c92d9701249e6daf132087756a88cbf2bb2a3Vendor (CNA)
Linux Linuxcce42014415cecd98aa49b3950e7b02ee7c81268Vendor (CNA)
debian:linux6.1.180-1 · 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.

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.

No nightly-computed relations.

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

Weakness class (CWE)

—

CVSS vector

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

nvd-secondary

Attack context

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records