Linux Kernel up to 6.18.55/7.2.9/7.3-rc5 netfs netfs_read_gaps race condition

| CVSS Meta Temp Score | Current Exploit Price (≈) | CTI Interest Score |
|---|---|---|
| 9.5 | $0-$5k | 2.66 |
Summary
A vulnerability, which was classified as very critical, has been found in Linux Kernel up to 6.18.55/7.2.9/7.3-rc5. Affected is the function netfs_read_gaps of the component netfs. This manipulation causes race condition.
The identification of this vulnerability is CVE-2026-98843. It is possible to initiate the attack remotely. There is no exploit available.
It is advisable to upgrade the affected component.
Details
A vulnerability classified as very critical was found in Linux Kernel up to 6.18.55/7.2.9/7.3-rc5. Affected by this vulnerability is the function netfs_read_gaps of the component netfs. The manipulation with an unknown input leads to a race condition vulnerability. The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:
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.
The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-98843 since 09/25/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/19/2026).
The vulnerability scanner Nessus provides a plugin with the ID 367173 (Linux Distros Unpatched Vulnerability : CVE-2026-98843), which helps to determine the existence of the flaw in a target environment.
Upgrading to version 6.18.56, 7.2.10 or 7.3-rc6 eliminates this vulnerability. Applying the patch 512eaf01ffabf4258e945016b50df5aed940b705/2a62fe628a877c249c8286b157ee99d82840d9dc/8db55c5cd831a786a1a2a2d391aa80354535a353 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.
The vulnerability is also documented in the vulnerability database at Tenable (367173). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Product
Type
Vendor
Name
Version
- 6.18.0
- 6.18.1
- 6.18.2
- 6.18.3
- 6.18.4
- 6.18.5
- 6.18.6
- 6.18.7
- 6.18.8
- 6.18.9
- 6.18.10
- 6.18.11
- 6.18.12
- 6.18.13
- 6.18.14
- 6.18.15
- 6.18.16
- 6.18.17
- 6.18.18
- 6.18.19
- 6.18.20
- 6.18.21
- 6.18.22
- 6.18.23
- 6.18.24
- 6.18.25
- 6.18.26
- 6.18.27
- 6.18.28
- 6.18.29
- 6.18.30
- 6.18.31
- 6.18.32
- 6.18.33
- 6.18.34
- 6.18.35
- 6.18.36
- 6.18.37
- 6.18.38
- 6.18.39
- 6.18.40
- 6.18.41
- 6.18.42
- 6.18.43
- 6.18.44
- 6.18.45
- 6.18.46
- 6.18.47
- 6.18.48
- 6.18.49
- 6.18.50
- 6.18.51
- 6.18.52
- 6.18.53
- 6.18.54
- 6.18.55
- 7.2.0
- 7.2.1
- 7.2.2
- 7.2.3
- 7.2.4
- 7.2.5
- 7.2.6
- 7.2.7
- 7.2.8
- 7.2.9
- 7.3-rc1
- 7.3-rc2
- 7.3-rc3
- 7.3-rc4
- 7.3-rc5
License
Website
- Vendor: https://www.kernel.org/
CPE 2.3
CPE 2.2
CVSSv4
VulDB Vector: 🔒VulDB Reliability: 🔍
CVSSv3
VulDB Meta Base Score: 9.9VulDB Meta Temp Score: 9.5
VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍
CVSSv2
| AV | AC | Au | C | I | A |
|---|---|---|---|---|---|
| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| 💳 | 💳 | 💳 | 💳 | 💳 | 💳 |
| Vector | Complexity | Authentication | Confidentiality | Integrity | Availability |
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| Unlock | Unlock | Unlock | Unlock | Unlock | Unlock |
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍
Exploiting
Class: Race conditionCWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒
Physical: No
Local: No
Remote: Yes
Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒
| 0-Day | Unlock | Unlock | Unlock | Unlock |
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Nessus ID: 367173
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-98843
Threat Intelligence
Interest: 🔍Active Actors: 🔍
Active APT Groups: 🔍
Countermeasures
Recommended: UpgradeStatus: 🔍
0-Day Time: 🔒
Upgrade: Kernel 6.18.56/7.2.10/7.3-rc6
Patch: 512eaf01ffabf4258e945016b50df5aed940b705/2a62fe628a877c249c8286b157ee99d82840d9dc/8db55c5cd831a786a1a2a2d391aa80354535a353
Timeline
09/25/2026 CVE reserved10/18/2026 Advisory disclosed
10/18/2026 VulDB entry created
10/19/2026 VulDB entry last update
Sources
Vendor: kernel.orgAdvisory: git.kernel.org
Status: Confirmed
CVE: CVE-2026-98843 (🔒)
GCVE (CVE): GCVE-0-2026-98843
GCVE (VulDB): GCVE-100-421849
Entry
Created: 10/18/2026 18:28Updated: 10/19/2026 06:08
Changes: 10/18/2026 18:28 (59), 10/19/2026 06:08 (2)
Complete: 🔍
Cache ID: 216::103
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
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