CVE-2026-98872VulnerabilityPublished 24 Oct 2026Updated 2 Nov 2026

Microsoft · freevxfs: don't BUG() on unknown typed-extent type

Affects MicrosoftSource GCVE Database

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Authoritative record:CVE-2026-98872· Medium

Not known to be exploited · fixed in fe40a19d571cbb584eea46038ee919d8712b2d2c : update Microsoft when convenient.

Data as of 2 Nov 2026, 10:58 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in fe40a19d571cbb584eea46038ee919d8712b2d2c, f1f2d54a576f0e4133b979e545abcfefd439c300, 1284d687d46953fff9c0d969df108114611aca8b +4

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 2 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

microsoft-security-response-ce

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < fe40a19d571cbb584eea46038ee919d8712b2d2c	Fixed in fe40a19d571cbb584eea46038ee919d8712b2d2c
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < f1f2d54a576f0e4133b979e545abcfefd439c300	Fixed in f1f2d54a576f0e4133b979e545abcfefd439c300
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 1284d687d46953fff9c0d969df108114611aca8b	Fixed in 1284d687d46953fff9c0d969df108114611aca8b
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 704d48d81dc41470e108811c32c577ada66192d4	Fixed in 704d48d81dc41470e108811c32c577ada66192d4
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 500e9d5bf9eff2096a21b7ac25a0a06ca46ab821	Fixed in 500e9d5bf9eff2096a21b7ac25a0a06ca46ab821
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 405f13d7b270913e06e8e2b4de568985f94ef7d6	Fixed in 405f13d7b270913e06e8e2b4de568985f94ef7d6

Description

CVE-2026-98872 concerns an issue in Microsoft software versions 3.0 and 4.0 where the freevxfs component improperly handles unknown typed-extent types by triggering a BUG() condition. This behavior could lead to unexpected crashes or instability in the affected software.

Impact

The impact of this vulnerability is a potential denial of service due to software crashes triggered by unknown typed-extent types. There is no information about privilege escalation, data corruption, or remote code execution. No active exploitation has been reported.

Summary

The vulnerability identified as CVE-2026-98872 involves the freevxfs component in Microsoft software versions 3.0 and 4.0. When encountering an unknown typed-extent type, the software executes a BUG() call, which is typically used to indicate a critical error and halt execution. This can cause the software to crash or behave unpredictably. No CVSS score or detailed impact metrics are provided, and no known exploits in the wild have been reported as of the published date.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 2 Nov 2026, 09:30 UTC

Technical details

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