5.5

CVE-2026-31509: linux Improper Locking

CVSS: 5.5v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-31509DEBIAN-CVE-2026-31509
Published 22-04-2026Last modified 11-05-2026
Open JSON

Vulnerability summary

CVE-2026-31509 is a medium (CVSS 5.5) Improper Locking vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.13%
0%100%
Low · +0.03 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 41 · Related 39
MGASA-2026-0108MGASA-2026-0110OPENSUSE-SU-2026:21555-1SUSE-SU-2026:23066-1SUSE-SU-2026:23068-1SUSE-SU-2026:23193-1

Timeline

  1. 22-04-2026
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: nfc: nci: fix circular locking dependency in nci_close_device nci_close_device() flushes rx_wq and tx_wq while holding req_lock. This causes a circular locking dependency because nci_rx_work() running on rx_wq can end up taking req_lock too: nci_rx_work -> nci_rx_data_packet -> nci_data_exchange_complete -> __sk_destruct -> rawsock_destruct -> nfc_deactivate_target -> nci_deactivate_target -> nci_request -> mutex_lock(&ndev->req_lock) Move the flush of rx_wq after req_lock has been released. This should safe (I think) because NCI_UP has already been cleared and the transport is closed, so the work will see it and return -ENETDOWN. NIPA has been hitting this running the nci selftest with a debug kernel on roughly 4% of the runs.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.13%

Chance of exploitation in the next 30 days

Percentile

2%

Versus all other CVEs

30-day change

+0.03 pp

From 0.10% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.13%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu157 products
  • linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 6a2968aaf50c7a22fced77a5e24aa636281efca8, < 7ed00a3edc8597fe2333f524401e2889aa1b5edf | ≥ 6a2968aaf50c7a22fced77a5e24aa636281efca8, < 5eef9ebec7f5738f12cadede3545c05b34bf5ac3 | ≥ 6a2968aaf50c7a22fced77a5e24aa636281efca8, < ca54e904a071aa65ef3ad46ba42d51aaac6b73b4 | ≥ 6a2968aaf50c7a22fced77a5e24aa636281efca8, < eb435d150ca74b4d40f77f1a2266f3636ed64a79 | ≥ 6a2968aaf50c7a22fced77a5e24aa636281efca8, < 1edc12d2bbcb7a8d0f1088e6fccb9d8c01bb1289 | ≥ 6a2968aaf50c7a22fced77a5e24aa636281efca8, < d89b74bf08f067b55c03d7f999ba0a0e73177eb3 | ≥ 6a2968aaf50c7a22fced77a5e24aa636281efca8, < 09143c0e8f3b03517e6233aad42f45c794d8df8e | ≥ 6a2968aaf50c7a22fced77a5e24aa636281efca8, < 4527025d440ce84bf56e75ce1df2e84cb8178616 | 3.2
  • linux_kernel≥ 3.2.1, < 5.10.253 | ≥ 5.11, < 5.15.203 | ≥ 5.16, < 6.1.168 | ≥ 6.2, < 6.6.131 | ≥ 6.7, < 6.12.80 | ≥ 6.13, < 6.18.21 | ≥ 6.19, < 6.19.11 | 3.2 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6 | 7.0:rc7
Debian1 product
  • linux< 6.1.170-1 | < 6.12.85-1 | < 6.19.11-1

3 vendors · 160 products

References

40 links
Show all 40 references