5.5

CVE-2026-52944: linux

CVSS: 5.5v3.1MediumModified
AliasesUBUNTU-CVE-2026-52944DEBIAN-CVE-2026-52944CGA-67qg-c3w7-c9mc
Published 24-06-2026Last modified 14-09-2026
Open JSON

Vulnerability summary

CVE-2026-52944 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 1.7% 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
0.12%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 17 · Related 17
USN-8566-1USN-8568-1USN-8569-1USN-8593-1USN-8603-1USN-8618-1

Timeline

  1. 24-06-2026
    PublishedVulnerability first disclosed.
  2. 14-09-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTL_SET_SPARSE FSCTL_SET_SPARSE in fsctl_set_sparse() modifies the file's sparse attribute and saves it through xattr without any permission checks. This exposes two issues: 1) A client on a read-only share can change the sparse attribute on files it opened, even though the share is read-only. Other FSCTL write operations already check test_tree_conn_flag(work->tcon, KSMBD_TREE_CONN_FLAG_WRITABLE), but FSCTL_SET_SPARSE does not. 2) Even on writable shares, clients without FILE_WRITE_DATA or FILE_WRITE_ATTRIBUTES access should not modify the sparse attribute. Similar handle-level checks exist in other functions but are missing here. Add both share-level writable check and per-handle access check. Use goto out on error to avoid leaking file references.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.12%

Chance of exploitation in the next 30 days

Percentile

2%

Versus all other CVEs

30-day change

0.00 pp

From 0.12% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.12%

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

No weakness data has been published for this record.

Affected systems

Ubuntu155 products
  • linuxAll versions (No fix recorded) | < 6.8.0-146.146 | < 7.0.0-28.28
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 6.8.0-1066.69 | < 7.0.0-1009.9
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Chainguard5 products
  • linux-aws-6.12All versions (No fix recorded)
  • linux-azure-6.12All versions (No fix recorded)
  • linux-gcp-6.12All versions (No fix recorded)
  • linux-qemu-6.12All versions (No fix recorded)
  • linux-vmware-6.12All versions (No fix recorded)
Debian2 products
  • linuxAll versions (No fix recorded) | < 6.1.190-1 | < 6.12.111-1 | < 7.0.12-1
  • linux-6.12< 6.12.111-1~deb12u1
Linux2 products
  • linux≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < ef664475c1bf1a27d45dae6848ca9c9c4d86853f | ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < 3a9a0a1c38ef90788f5d7c4b29903c8b220f744a | ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < 3127a884525dc8ca4def73254bfcd3ccef0bf812 | ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < c5ab11263e3c89aa7989afc5374ef7743e092fd0 | ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < de9eb0b44fa9123170e6245b49638e0e453c10f8 | ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < aef151bcfa494bfe983669de2726734b534adb73 | ≥ e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9, < cc57232cae23c0df91b4a59d0f519141ce9b5b02 | 5.15
  • linux_kernel≥ 5.15, < 6.6.143 | ≥ 6.7, < 6.18.35 | ≥ 6.19, < 7.0.12 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3 | 7.1:rc4 | 7.1:rc5

4 vendors · 164 products

References

28 links
Show all 28 references