CVE-2026-98582: Linux kernel · nfc: st21nfca: validate received frame size
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.1 Medium.
Data as of 28 Oct 2026, 01:28 UTC
CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: nfc: st21nfca: validate received frame size st21nfca_hci_i2c_repack() trims a received frame at its EOF marker before removing byte stuffing. It then assumes the truncated frame contains the LLC header and two CRC bytes, and it unconditionally reads the byte after an escape marker. A malformed frame can place EOF immediately after the start marker or can end its data portion with an escape marker. The former leaves too few bytes for check_crc(), while the latter makes the unstuffing loop read past the current skb length. Require the minimum framing bytes both before and after unstuffing. Use separate input and output cursors while removing byte stuffing, and reject an escape marker without its encoded byte. This keeps malformed frames within the received frame boundary before CRC processing.
References
- ubuntu.com/security/CVE-2026-98582 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-98582 (opens in a new tab)
- git.kernel.org/stable/c/f526c218a149a30f110ce434ff17e033042404b8 (opens in a new tab)
- git.kernel.org/stable/c/d0596ee6c4b928a5c288790522a7495ee867da72 (opens in a new tab)
- git.kernel.org/stable/c/57919d0662d8856211b794140172e51ca389f23d (opens in a new tab)
- git.kernel.org/stable/c/8934d2889ae16a7c77520e002398d0689c1ecea5 (opens in a new tab)
- git.kernel.org/stable/c/d4008c3499dba7829bfe002edd99a8bff8ae3a7c (opens in a new tab)
- git.kernel.org/stable/c/7b996cc06dda54c02a5aa607bda01109f0ac51e6 (opens in a new tab)
- git.kernel.org/stable/c/91be5161f37b0a2795ad6806d69be5fa74522e5c (opens in a new tab)
- git.kernel.org/stable/c/a653c01ce447f10c36b901646888c0330363af4f (opens in a new tab)