VulnerabilityPublished 23 Oct 2026

CVE-2026-98879: Linux kernel · isofs: handle set_blocksize failures

Source GCVE Database

Authoritative record:CVE-2026-98879· Medium

Not known to be exploited · fixed in cebde6d88e34396c29f2f001d90e921677cc17d6 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 12:30 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in cebde6d88e34396c29f2f001d90e921677cc17d6, 9584ab6283721e5aab485c79bd06c2f78d89e55c, 61f277bf35f533b602984f0e55900111fe52f31a +4

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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.

ghsa-q9wc-mgjh-78f8

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < cebde6d88e34396c29f2f001d90e921677cc17d6	Fixed in cebde6d88e34396c29f2f001d90e921677cc17d6
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 9584ab6283721e5aab485c79bd06c2f78d89e55c	Fixed in 9584ab6283721e5aab485c79bd06c2f78d89e55c
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 61f277bf35f533b602984f0e55900111fe52f31a	Fixed in 61f277bf35f533b602984f0e55900111fe52f31a
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 28d1f6aa14f5924e36602b7a31c9141d34de0b9c	Fixed in 28d1f6aa14f5924e36602b7a31c9141d34de0b9c
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 25ef4c4d9f0e96fb89c0ae0d7127c3f12a31bc32	Fixed in 25ef4c4d9f0e96fb89c0ae0d7127c3f12a31bc32
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 9c97e3b1152d3092581745189f5d2f04c6404ef9	Fixed in 9c97e3b1152d3092581745189f5d2f04c6404ef9

AI-suggested

A fix has been implemented in the Linux kernel to handle set_blocksize failures properly in the isofs filesystem code. Users should apply the official kernel update that includes this fix. Patch status is not explicitly confirmed here; check the vendor or Linux kernel advisory for the exact fixed versions and update accordingly.

Description

A vulnerability in the Linux kernel's isofs filesystem code was resolved. The issue involved improper handling of set_blocksize failures because isofs uses buffer_heads, which do not handle block sizes larger than PAGE_SIZE correctly. This could cause a kernel BUG_ON failure during mounting due to an offset exceeding the folio size.

References

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