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NVD / CVE Program· CNA Linux

CVE-2026-80823: nfc: st21nfca: validate ATR_REQ length against the received frame

Noroxi assessment

Priority: Monitor (action score 0/100)

  • 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: 0.19% (FIRST EPSS).
  • Fixed version: Linux Linux 0f344944c506b4f02d2b098489f7268b438c369e, 2c1ad291f4cdc357f9527b688c6fda9c6ffa7890, 304f5b414f4051d324b8c4a3ab0e79f7dc7e150e.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0f344944c506b4f02d2b098489f7268b438c369e, 2c1ad291f4cdc357f9527b688c6fda9c6ffa7890, 304f5b414f4051d324b8c4a3ab0e79f7dc7e150e 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: st21nfca: validate ATR_REQ length against the received frame st21nfca_tm_recv_atr_req() checks that the received ATR_REQ frame is at least ST21NFCA_ATR_REQ_MIN_SIZE and that the self-declared atr_req->length is at least sizeof(struct st21nfca_atr_req), but never checks that atr_req->length does not exceed the actual received length (skb->len). st21nfca_tm_send_atr_res() then trusts the declared length: gb_len = atr_req->length - sizeof(struct st21nfca_atr_req); ... memcpy(atr_res->gbi, atr_req->gbi, gb_len); so an RF peer that sends a short frame but sets atr_req->length larger than the frame makes gb_len exceed the general bytes actually present, and the memcpy reads out of bounds past the received skb. Those bytes are placed in the ATR_RES and sent back to the peer (kernel-memory disclosure to a proximity attacker); a larger declared length is an out-of-bounds read (DoS). Reject frames whose declared length exceeds the received length. The adjacent nfc_tm_activated() path in the same function already derives its general-bytes length from skb->len rather than the declared field. Found by 0sec (https://0sec.ai) using automated source analysis; the missing bound is evident from source. Compile-tested.

—No exploit Fix available
Published
Sep 4, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 9th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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  • A fix has been released

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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.

—

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

    • 3.17affected
    • 1892bf844ea0261736bd5e75546fc996e9daeedf and later · before 785df00bb3ae3206674a43284eb06dac575b5c64affected · git
    • 1892bf844ea0261736bd5e75546fc996e9daeedf and later · before 2c1ad291f4cdc357f9527b688c6fda9c6ffa7890affected · git
    • 1892bf844ea0261736bd5e75546fc996e9daeedf and later · before dd26d30f40c43ad9cfe2f25c6ea0ead1dd51d5aaaffected · git
    • 1892bf844ea0261736bd5e75546fc996e9daeedf and later · before 9635507fe82949e429b3cd938876a9917125b151affected · git
    • 1892bf844ea0261736bd5e75546fc996e9daeedf and later · before 0f344944c506b4f02d2b098489f7268b438c369eaffected · git
    • 1892bf844ea0261736bd5e75546fc996e9daeedf and later · before bfcca5f42c9aa4eadef1e5fe7bb23783d7fcc96daffected · git
    • 1892bf844ea0261736bd5e75546fc996e9daeedf and later · before 304f5b414f4051d324b8c4a3ab0e79f7dc7e150eaffected · git
    • 1892bf844ea0261736bd5e75546fc996e9daeedf and later · before f33cecf69095c43be88567fef92b180b858f7369affected · git
    • 1892bf844ea0261736bd5e75546fc996e9daeedf and later · before 5cdcca5d62a66eda6b774110a44cba67bc1a8d1daffected · git

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.187-16.1.187-1
Debian:12linux-6.12before 6.12.107-1~deb12u16.12.107-1~deb12u1
Debian:13linuxbefore 6.12.107-16.12.107-1
Debian:14linuxbefore 7.1.12-17.1.12-1

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-2026-80821Sep 4, 2026 · nvmet: pci-epf: put CQ ref on create_cq mapping failure
    0Monitor
  • ← EarlierCVE-2026-80822Sep 4, 2026 · mailbox: mchp-ipc-sbi: Add null check for devm_kasprintf()
    0Monitor
  • Later →CVE-2026-80824Sep 4, 2026 · usb: usbfs: fix use-after-free of usb_device in usbdev_release()
    0Monitor

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 Linux0f344944c506b4f02d2b098489f7268b438c369eVendor (CNA)
Linux Linux2c1ad291f4cdc357f9527b688c6fda9c6ffa7890Vendor (CNA)
Linux Linux304f5b414f4051d324b8c4a3ab0e79f7dc7e150eVendor (CNA)
Linux Linux5cdcca5d62a66eda6b774110a44cba67bc1a8d1dVendor (CNA)
Linux Linux785df00bb3ae3206674a43284eb06dac575b5c64Vendor (CNA)
Linux Linux9635507fe82949e429b3cd938876a9917125b151Vendor (CNA)
Linux Linuxbfcca5f42c9aa4eadef1e5fe7bb23783d7fcc96dVendor (CNA)
Linux Linuxdd26d30f40c43ad9cfe2f25c6ea0ead1dd51d5aaVendor (CNA)
Linux Linuxf33cecf69095c43be88567fef92b180b858f7369Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
debian:linux6.1.187-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.107-1~deb12u1 · 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).

National notice (Türkiye Cybersecurity Directorate / USOM)

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

All national notices →

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

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✗ → ✓

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References

Show all references (8 more)

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

All records