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NVD / CVE Program· CNA Linux

CVE-2026-43098: nfc: s3fwrn5: allocate rx skb before consuming bytes

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: 0.12% (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 09822d3d6f68a0cdc4626e0c507324a4927f55a9, 20a57de2e79b797ed75382659d52bf4c7d9cb446, 5c14a19d5b1645cce1cb1252833d70b23635b632.

Low priority for now. Upgrade to Linux Linux 09822d3d6f68a0cdc4626e0c507324a4927f55a9, 20a57de2e79b797ed75382659d52bf4c7d9cb446, 5c14a19d5b1645cce1cb1252833d70b23635b632 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: nfc: s3fwrn5: allocate rx skb before consuming bytes s3fwrn82_uart_read() reports the number of accepted bytes to the serdev core. The current code consumes bytes into recv_skb and may already deliver a complete frame before allocating a fresh receive buffer. If that alloc_skb() fails, the callback returns 0 even though it has already consumed bytes, and it leaves recv_skb as NULL for the next receive callback. That breaks the receive_buf() accounting contract and can also lead to a NULL dereference on the next skb_put_u8(). Allocate the receive skb lazily before consuming the next byte instead. If allocation fails, return the number of bytes already accepted.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 6, 2026
Updated
Jun 17, 2026
EPSS
0.1% · 2th percentile
CWE
—

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 · 0.1%

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

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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

Affected versions

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

  • linux linux kernel5.11 and later · before 6.6.136
  • linux linux kernel6.7 and later · before 6.12.83
  • linux linux kernel6.13 and later · before 6.18.24
  • linux linux kernel6.19 and later · before 6.19.14
  • linux linux kernel7.0

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

    • 5.11affected
    • 3f52c2cb7e3ada37513dabb69a22cf917dba754f and later · before 20a57de2e79b797ed75382659d52bf4c7d9cb446affected · git
    • 3f52c2cb7e3ada37513dabb69a22cf917dba754f and later · before e4ab0fd1c91882f2a7846b1817781c8741f7f315affected · git
    • 3f52c2cb7e3ada37513dabb69a22cf917dba754f and later · before d8c2aa3c4a1ec530a485e46a1c4f1a118bb00156affected · git
    • 3f52c2cb7e3ada37513dabb69a22cf917dba754f and later · before 7c31f7a599cf00fad3c204092a91a924126c67e4affected · git
    • 3f52c2cb7e3ada37513dabb69a22cf917dba754f and later · before 6d931680a9851481c3243689488eafed08eeff71affected · git
    • 3f52c2cb7e3ada37513dabb69a22cf917dba754f and later · before 09822d3d6f68a0cdc4626e0c507324a4927f55a9affected · git
    • 3f52c2cb7e3ada37513dabb69a22cf917dba754f and later · before 5c14a19d5b1645cce1cb1252833d70b23635b632affected · git
    • before 5.11not affected · semver
    • 5.15.209 and later · up to and including 5.15.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.14-16.19.14-1

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-2026-43096May 6, 2026 · mshv: Fix infinite fault loop on permission-denied GPA intercepts
    22Monitor
  • ← EarlierCVE-2026-43097May 6, 2026 · PCI: hv: Fix double ida_free in hv_pci_probe error path
    31Monitor
  • Later →CVE-2026-43100May 6, 2026 · bridge: guard local VLAN-0 FDB helpers against NULL vlan group
    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 Linux09822d3d6f68a0cdc4626e0c507324a4927f55a9Vendor (CNA)
Linux Linux20a57de2e79b797ed75382659d52bf4c7d9cb446Vendor (CNA)
Linux Linux5c14a19d5b1645cce1cb1252833d70b23635b632Vendor (CNA)
Linux Linux6d931680a9851481c3243689488eafed08eeff71Vendor (CNA)
Linux Linux7c31f7a599cf00fad3c204092a91a924126c67e4Vendor (CNA)
Linux Linuxd8c2aa3c4a1ec530a485e46a1c4f1a118bb00156Vendor (CNA)
Linux Linuxe4ab0fd1c91882f2a7846b1817781c8741f7f315Vendor (CNA)
debian:linux6.1.176-1 · 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.

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
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)

—

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.

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

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