NVD / CVE Program· CNA Linux

CVE-2026-31622: NFC: digital: Bounds check NFC-A cascade depth in SDD response handler

HighCVSS 8.8 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 35/100)

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: 0.28% (FIRST EPSS).
Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 1bec5698b55aa2be5c3b983dba657c01d0fd3dbc, 20663102c14566e900e1d2f679e30b7f1694f387, 2819f34e08bdffb6f06a51c67948ec5737fb166a; azl3 kernel 6.6.134.1-2 on Azure Linux 3.0 6.6.137.1-1.

Low priority for now. Upgrade to Linux Linux 1bec5698b55aa2be5c3b983dba657c01d0fd3dbc, 20663102c14566e900e1d2f679e30b7f1694f387, 2819f34e08bdffb6f06a51c67948ec5737fb166a; azl3 kernel 6.6.134.1-2 on Azure Linux 3.0 6.6.137.1-1 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: digital: Bounds check NFC-A cascade depth in SDD response handler The NFC-A anti-collision cascade in digital_in_recv_sdd_res() appends 3 or 4 bytes to target->nfcid1 on each round, but the number of cascade rounds is controlled entirely by the peer device. The peer sets the cascade tag in the SDD_RES (deciding 3 vs 4 bytes) and the cascade-incomplete bit in the SEL_RES (deciding whether another round follows). ISO 14443-3 limits NFC-A to three cascade levels and target->nfcid1 is sized accordingly (NFC_NFCID1_MAXSIZE = 10), but nothing in the driver actually enforces this. This means a malicious peer can keep the cascade running, writing past the heap-allocated nfc_target with each round. Fix this by rejecting the response when the accumulated UID would exceed the buffer. Commit e329e71013c9 ("NFC: nci: Bounds check struct nfc_target arrays") fixed similar missing checks against the same field on the NCI path.

BDU:2026-11324

Published: Apr 24, 2026
Updated: Nov 11, 2026
EPSS: 0.2% · 21th percentile
CWE: CWE-120

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CNA vs NVD score

NVD: —
CNA · Linux: 8.8; 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.

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.

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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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_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
- 3.13affected
- 2c66daecc4092e6049673c281b2e6f0d5e59a94c and later · before 9ba6bb09e00b922d902f684f575779e5433fe6e3affected · git
- 2c66daecc4092e6049673c281b2e6f0d5e59a94c and later · before f83b399aa05a0712e3b1569a30d3d90b3533d2efaffected · git
- 2c66daecc4092e6049673c281b2e6f0d5e59a94c and later · before 20663102c14566e900e1d2f679e30b7f1694f387affected · git
- 2c66daecc4092e6049673c281b2e6f0d5e59a94c and later · before 2819f34e08bdffb6f06a51c67948ec5737fb166aaffected · git
- 2c66daecc4092e6049673c281b2e6f0d5e59a94c and later · before 1bec5698b55aa2be5c3b983dba657c01d0fd3dbcaffected · git
- 2c66daecc4092e6049673c281b2e6f0d5e59a94c and later · before 5a59bf70c38ee1eb4be03bab830bbc3a6f0bd1f1affected · git
- 2c66daecc4092e6049673c281b2e6f0d5e59a94c and later · before 8d9d9bf3565271ca7ab9c716a94e87296177e7baaffected · git
- 2c66daecc4092e6049673c281b2e6f0d5e59a94c and later · before cc024a3de265ef6c58957f4990eccb9f806208cbaffected · git
- 2c66daecc4092e6049673c281b2e6f0d5e59a94c and later · before 46ce8be2ced389bccd84bcc04a12cf2f4d0c22d1affected · git

Affected versions · NVD (5)

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

linux linux kernel3.13 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 and later · before 7.0.1

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.176-1	6.1.176-1
Debian:13	linux	before 6.12.85-1	6.12.85-1
Debian:14	linux	before 6.19.14-1	6.19.14-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

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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
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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-2026-31620Apr 24, 2026 · ALSA: usx2y: us144mkii: fix NULL deref on missing interface 0
18Monitor
← EarlierCVE-2026-31621Apr 24, 2026 · bnge: return after auxiliary_device_uninit() in error path
22Monitor
Later →CVE-2026-31623Apr 24, 2026 · net: usb: cdc-phonet: fix skb frags[] overflow in rx_complete()
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 / package	Fixed version	Source
Linux Linux	1bec5698b55aa2be5c3b983dba657c01d0fd3dbc	Vendor (CNA)
Linux Linux	20663102c14566e900e1d2f679e30b7f1694f387	Vendor (CNA)
Linux Linux	2819f34e08bdffb6f06a51c67948ec5737fb166a	Vendor (CNA)
Linux Linux	46ce8be2ced389bccd84bcc04a12cf2f4d0c22d1	Vendor (CNA)
Linux Linux	5a59bf70c38ee1eb4be03bab830bbc3a6f0bd1f1	Vendor (CNA)
Linux Linux	8d9d9bf3565271ca7ab9c716a94e87296177e7ba	Vendor (CNA)
Linux Linux	9ba6bb09e00b922d902f684f575779e5433fe6e3	Vendor (CNA)
Linux Linux	cc024a3de265ef6c58957f4990eccb9f806208cb	Vendor (CNA)
Linux Linux	f83b399aa05a0712e3b1569a30d3d90b3533d2ef	Vendor (CNA)
azl3 kernel 6.6.134.1-2 on Azure Linux 3.0	6.6.137.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.176-1 · Debian:12	Package 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.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-6388786 days apartscsi: target: iscsi: Bound iscsi_encode_text_output() appends to rsp_buf
39Monitor
CVE-2026-4633246 days apartgreybus: gb-beagleplay: bound bootloader receive buffering
32Monitor
CVE-2026-4614534 days apartRDMA/mana: Validate rx_hash_key_len
31Monitor
CVE-2025-39727229 days apartmm: swap: fix potential buffer overflow in setup_clusters()
31Monitor
CVE-2025-37891340 days apartALSA: ump: Fix buffer overflow at UMP SysEx message conversion
31Monitor
CVE-2025-37803351 days apartudmabuf: fix a buf size overflow issue during udmabuf creation
31Monitor

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

Technical details

Attack conditions

Someone on the same network segment 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: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Adjacent
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

CVSS vector

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

nvd-secondary

Root cause

When data is copied, the source length is not compared with the size of the destination buffer. Excess data overwrites adjacent memory.

The bug in code

The whole CWE-120 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1char buf[256];
2memcpy(buf, pkt->data, pkt->len);

Fixed

1char buf[256];
2if (pkt->len > sizeof(buf)) {
3  return -EINVAL;
4}
5memcpy(buf, pkt->data, pkt->len);

Attack context

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

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log (1)

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

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

References

git.kernel.org/stable/c/1bec5698b55aa2be5c3b983dba657c01d0fd3dbc

Show all references (9 more)

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

All records