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NVD / CVE Program· CNA Linux

CVE-2026-43452: netfilter: x_tables: guard option walkers against 1-byte tail reads

HighCVSS 8.2 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 32/100)

  • 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: 0.54% (FIRST EPSS).
  • 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 5b18b8b35c7cded2d17b2b2604c9b0694ff48d1c, 9b94f0e42ed248eb31929da84ed9f5310d7ff540, ae1e1267650638136b84c23f2b31250f0ccb6823.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 5b18b8b35c7cded2d17b2b2604c9b0694ff48d1c, 9b94f0e42ed248eb31929da84ed9f5310d7ff540, ae1e1267650638136b84c23f2b31250f0ccb6823 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: x_tables: guard option walkers against 1-byte tail reads When the last byte of options is a non-single-byte option kind, walkers that advance with i += op[i + 1] ? : 1 can read op[i + 1] past the end of the option area. Add an explicit i == optlen - 1 check before dereferencing op[i + 1] in xt_tcpudp and xt_dccp option walkers.

Published
May 8, 2026
Updated
Nov 11, 2026
EPSS
0.5% · 45th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
none
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
8.2
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-2026-43452

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

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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.

VendorProduct
linuxlinux kernel

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

    • 2.6.16affected
    • 2e4e6a17af35be359cc8f1c924f8f198fbd478cc and later · before c2a445367a496a3c25dbc940c10c8bd1cfd4c14aaffected · git
    • 2e4e6a17af35be359cc8f1c924f8f198fbd478cc and later · before ae1e1267650638136b84c23f2b31250f0ccb6823affected · git
    • 2e4e6a17af35be359cc8f1c924f8f198fbd478cc and later · before c39f84e4be1be63fc60ca7141ea7b76edcea5907affected · git
    • 2e4e6a17af35be359cc8f1c924f8f198fbd478cc and later · before 9b94f0e42ed248eb31929da84ed9f5310d7ff540affected · git
    • 2e4e6a17af35be359cc8f1c924f8f198fbd478cc and later · before 5b18b8b35c7cded2d17b2b2604c9b0694ff48d1caffected · git
    • 2e4e6a17af35be359cc8f1c924f8f198fbd478cc and later · before bc18551c6169eac5ed813778d3e3e484002dbbe5affected · git
    • 2e4e6a17af35be359cc8f1c924f8f198fbd478cc and later · before d04800323336eebf441d153f43234eac9b833d36affected · git
    • 2e4e6a17af35be359cc8f1c924f8f198fbd478cc and later · before cfe770220ac2dbd3e104c6b45094037455da81d4affected · git
    • before 2.6.16not affected · semver
Affected versions · NVD (8)

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

  • linux linux kernel2.6.16 and later · before 5.10.253
  • linux linux kernel5.11 and later · before 5.15.203
  • linux linux kernel5.16 and later · before 6.1.167
  • linux linux kernel6.2 and later · before 6.6.130
  • linux linux kernel6.7 and later · before 6.12.78
  • linux linux kernel6.13 and later · before 6.18.19
  • linux linux kernel6.19 and later · before 6.19.9
  • linux linux kernel7.0

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.170-16.1.170-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.10-16.19.10-1

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-2026-43450May 8, 2026 · netfilter: nfnetlink_cthelper: fix OOB read in nfnl_cthelper_dump_table()
    28Monitor
  • ← EarlierCVE-2026-43451May 8, 2026 · netfilter: nfnetlink_queue: fix entry leak in bridge verdict error path
    22Monitor
  • Later →CVE-2026-43453May 8, 2026 · netfilter: nft_set_pipapo: fix stack out-of-bounds read in pipapo_drop()
    28Monitor

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 Linux5b18b8b35c7cded2d17b2b2604c9b0694ff48d1cVendor (CNA)
Linux Linux9b94f0e42ed248eb31929da84ed9f5310d7ff540Vendor (CNA)
Linux Linuxae1e1267650638136b84c23f2b31250f0ccb6823Vendor (CNA)
Linux Linuxbc18551c6169eac5ed813778d3e3e484002dbbe5Vendor (CNA)
Linux Linuxc2a445367a496a3c25dbc940c10c8bd1cfd4c14aVendor (CNA)
Linux Linuxc39f84e4be1be63fc60ca7141ea7b76edcea5907Vendor (CNA)
Linux Linuxcfe770220ac2dbd3e104c6b45094037455da81d4Vendor (CNA)
Linux Linuxd04800323336eebf441d153f43234eac9b833d36Vendor (CNA)
debian:linux6.1.170-1 · 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.

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

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
low · data can be read
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
Low
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-125 · Out-of-bounds Read

CVSS vector

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

ATT&CK techniques

—

References

Show all references (7 more)

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

All records