Unknown

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

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.

Published Sep 4, 2026 · Updated Oct 19, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.2% (30-day exploitation probability)+2

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.24%

ahead of 15% of scored CVEs · Oct 27, 2026

Affects

Linux

CVSS base

—

Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Linux	Linux	≥ 1892bf844ea0261736bd5e75546fc996e9daeedf and < 785df00bb3ae3206674a43284eb06dac575b5c64≥ 1892bf844ea0261736bd5e75546fc996e9daeedf and < 2c1ad291f4cdc357f9527b688c6fda9c6ffa7890≥ 1892bf844ea0261736bd5e75546fc996e9daeedf and < dd26d30f40c43ad9cfe2f25c6ea0ead1dd51d5aa≥ 1892bf844ea0261736bd5e75546fc996e9daeedf and < 9635507fe82949e429b3cd938876a9917125b151≥ 1892bf844ea0261736bd5e75546fc996e9daeedf and < 0f344944c506b4f02d2b098489f7268b438c369e≥ 1892bf844ea0261736bd5e75546fc996e9daeedf and < bfcca5f42c9aa4eadef1e5fe7bb23783d7fcc96d≥ 1892bf844ea0261736bd5e75546fc996e9daeedf and < 304f5b414f4051d324b8c4a3ab0e79f7dc7e150e≥ 1892bf844ea0261736bd5e75546fc996e9daeedf and < f33cecf69095c43be88567fef92b180b858f7369 and 2 more ≥ 1892bf844ea0261736bd5e75546fc996e9daeedf and < 5cdcca5d62a66eda6b774110a44cba67bc1a8d1dversion 3.17	Vulnerable	CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 27, 2026 · 12 reading(s) · max 0.24%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Not enough vector or weakness data: use the affected application’s logs as a starting point.

application logs

Timeline

What happened to this CVE, newest first.

2026
Record published
Oct 15, 2026
Affected products added · linux/linux
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Source status changed · → Received
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 4, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

1× References added · Oct 19, 2026 – Oct 19, 2026
1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

11 on the record

github.com/advisories/GHSA-vwx2-rh9p-3f2w
GitHub Security Advisories
git.kernel.org/stable/c/5cdcca5d62a66eda6b774110a44cba67bc1a8d1d
NIST National Vulnerability Database
git.kernel.org/stable/c/785df00bb3ae3206674a43284eb06dac575b5c64
NIST National Vulnerability Database
git.kernel.org/stable/c/dd26d30f40c43ad9cfe2f25c6ea0ead1dd51d5aa
NIST National Vulnerability Database
nvd.nist.gov/vuln/detail/CVE-2026-80823
GitHub Security Advisories
git.kernel.org/stable/c/9635507fe82949e429b3cd938876a9917125b151
NIST National Vulnerability Database
git.kernel.org/stable/c/f33cecf69095c43be88567fef92b180b858f7369
NIST National Vulnerability Database
git.kernel.org/stable/c/0f344944c506b4f02d2b098489f7268b438c369e
NIST National Vulnerability Database
git.kernel.org/stable/c/2c1ad291f4cdc357f9527b688c6fda9c6ffa7890
NIST National Vulnerability Database
git.kernel.org/stable/c/bfcca5f42c9aa4eadef1e5fe7bb23783d7fcc96d
NIST National Vulnerability Database
git.kernel.org/stable/c/304f5b414f4051d324b8c4a3ab0e79f7dc7e150e
NIST National Vulnerability Database

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

Unknown CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 7h
Unknown CVE-2026-99215 power: supply: core: prevent unregistering a power supply while a callback runs 7h
Unknown CVE-2026-99207 scsi: target: Disable interrupts while holding delayed_cmd_lock 7h
Unknown CVE-2026-99208 drm/xe/oa: Zero OA buffer at allocation 7h
Unknown CVE-2026-99209 drm/xe: skip eviction of a BO with no resource 7h
Unknown CVE-2026-99210 accel/rocket: clear rdev on device init failure 7h

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No CVSS score published by NVD, the CNA, CISA or GitHub so far.
No fixed version, patch or mitigation documented.
No CISA SSVC assessment.
No CWE classification.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-80823 is "nfc: st21nfca: validate ATR_REQ length against the received frame", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.24% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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