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Fencer Intel
high 8.2

CVE-2026-74221 json

U-Boot before 2026.10-rc5 Buffer Overflow via NFS READLINK

published last mo. modified last mo. also EUVD-2026-89434

cvss
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 27%
public exploits
0
none known

Summary

U-Boot before 2026.10-rc5 contains a buffer overflow in nfs_readlink_reply() function in net/nfs-common.c when processing NFS server responses. A malicious NFS server can send crafted READLINK replies with negative or oversized symlink length values to corrupt memory and crash the bootloader.

Patch / fix

  • u-boot u-boot 2026.10-rc5
  • u-boot Ubuntu 22.04 LTS 2022.01+dfsg-2ubuntu2.9
  • u-boot Ubuntu 24.04 LTS 2025.10-0ubuntu0.24.04.4
  • u-boot Ubuntu 26.10 2025.10-0ubuntu6
  • u-boot Ubuntu 26.04 LTS 2025.10-0ubuntu2.2
  • u-boot Ubuntu Pro 16.04 LTS 2016.01+dfsg1-2ubuntu5+esm2
  • u-boot Ubuntu Pro 18.04 LTS 2020.10+dfsg-1ubuntu0~18.04.3+esm2
  • u-boot Ubuntu Pro 20.04 LTS 2021.01+dfsg-3ubuntu0~20.04.6+esm2

ubuntu advisories UBUNTU-CVE-2026-74221

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Is CVE-2026-74221 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
last mo.

Exploit prediction

0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 8.8 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
CNA 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
CNA 4.0 8.8 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • u-boot u-boot

Classification

Weakness
  • CWE-195 Signed to Unsigned Conversion Error

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.