Stale data written back from netfs gaps in Linux kernel
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 1 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel from 6.12 contains a flaw in its netfs code. The function netfs_read_gaps() leaves gaps around a streaming write's dirty region unread on the server side, so a short or end-of-file response leaves stale folio content that is later written back. The fix zeroes the unread part of each gap after the read completes.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
In the Linux kernel, the following vulnerability has been resolved: netfs: zero gaps in read-gaps folio to avoid writing back stale data netfs_read_gaps() leaves gaps around a streaming write's dirty region unread on the server side, so a short/EOF response there left stale folio content that later got written back. Zero it after the read completes, not before: netfs_wait_for_read() returns rreq->transferred once ret >= 0, so build an iterator over the same bvec array the read used, advance past ret, and zero the rest. The dirty region already maps to sink pages in that array rather than the real folio, so this can't touch it, and only the actual shortfall gets zeroed instead of the whole gap upfront.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
Fixed versions are Linux kernel 6.18.56, 7.2.10 and 7.3. Red Hat lists Red Hat Enterprise Linux 10 as affected, with no fix available.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 6.18.56, 7.2.10, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
Not affected: 6 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98843
- 2026-10-18 Alias added: GHSA-3x6r-43qp-fxh7
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-24 Affected versions changed · Red Hat
- 2026-10-24 CVSS score added · Red Hat
- 2026-11-06 Affected versions changed · Red Hat
References
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- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
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Sources
- CVE-2026-98843 · CVE Program
- CVE-2026-98843 · NVD
- FIRST EPSS
- GHSA-3x6r-43qp-fxh7 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98843 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences