How severe is CVE-2026-40706?

CVE-2026-40706 has a CVSS 3.x base score of 8.4, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-40706 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40706?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-40706 have an EU (EUVD) identifier?

Yes. CVE-2026-40706 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24467.

When was CVE-2026-40706 published?

CVE-2026-40706 was published on 2026-04-21 and last updated on 2026-06-17.

CVE-2026-40706

CVE-2026-40706 is a high-severity vulnerability with a CVSS 3.x base score of 8.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-122.

Key facts

Severity: High (CVSS 3.x base score 8.4)
EPSS exploit prediction: 0% (6th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-24467
Weakness: CWE-122
Published: 2026-04-21
Last modified: 2026-06-17

Description

In NTFS-3G 2022.10.3 before 2026.2.25, a heap buffer overflow exists in ntfs_build_permissions_posix() in acls.c that allows an attacker to corrupt heap memory in the SUID-root ntfs-3g binary by crafting a malicious NTFS image. The overflow is triggered on the READ path (stat, readdir, open) when processing a security descriptor with multiple ACCESS_DENIED ACEs containing WRITE_OWNER from distinct group SIDs.

Frequently asked questions

What is CVE-2026-40706?: In NTFS-3G 2022.10.3 before 2026.2.25, a heap buffer overflow exists in ntfs_build_permissions_posix() in acls.c that allows an attacker to corrupt heap memory in the SUID-root ntfs-3g binary by crafting a malicious NTFS image. The overflow is triggered on the READ path (stat, readdir, open) when processing a security descriptor with multiple ACCESS_DENIED ACEs containing WRITE_OWNER from distinct group SIDs.
How severe is CVE-2026-40706?: CVE-2026-40706 has a CVSS 3.x base score of 8.4, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-40706 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40706?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-40706 have an EU (EUVD) identifier?: Yes. CVE-2026-40706 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-24467.
When was CVE-2026-40706 published?: CVE-2026-40706 was published on 2026-04-21 and last updated on 2026-06-17.

References

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