Linux: Out-of-bounds Read
CVE-2026-31435 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists versions 3e5fd8f53b575ff2188f82071da19c977ca56c41, 8f2f2bd128a8d9edbc1e785760da54ada3df69b7, 7e57523490cd2efb52b1ea97f2e0a74c0fb634cd as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.34% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 3e5fd8f53b575ff2188f82071da19c977ca56c41 or 8f2f2bd128a8d9edbc1e785760da54ada3df69b7 or 7e57523490cd2efb52b1ea97f2e0a74c0fb634cd, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.21 or 6.19.11, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | ee4cdf7ba857a894ad1650d6ab77669cbbfa329e up to, but not including, 3e5fd8f53b575ff2188f82071da19c977ca56c41; ee4cdf7ba857a894ad1650d6ab77669cbbfa329e up to, but not including, 8f2f2bd128a8d9edbc1e785760da54ada3df69b7; ee4cdf7ba857a894ad1650d6ab77669cbbfa329e up to, but not including, 7e57523490cd2efb52b1ea97f2e0a74c0fb634cd; 6.12 | 3e5fd8f53b575ff2188f82071da19c977ca56c41, 8f2f2bd128a8d9edbc1e785760da54ada3df69b7, 7e57523490cd2efb52b1ea97f2e0a74c0fb634cd |
| Linux | Linux Kernel | 6.12 up to, but not including, 6.18.21; 6.19 up to, but not including, 6.19.11; 7.0 | 6.18.21, 6.19.11 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by CNA.
Official description
In the Linux kernel, the following vulnerability has been resolved: netfs: Fix read abandonment during retry Under certain circumstances, all the remaining subrequests from a read request will get abandoned during retry. The abandonment process expects the 'subreq' variable to be set to the place to start abandonment from, but it doesn't always have a useful value (it will be uninitialised on the first pass through the loop and it may point to a deleted subrequest on later passes). Fix the first jump to "abandon:" to set subreq to the start of the first subrequest expected to need retry (which, in this abandonment case, turned out unexpectedly to no longer have NEED_RETRY set). Also clear the subreq pointer after discarding superfluous retryable subrequests to cause an oops if we do try to access it.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Read vulnerabilities
- 8.1 High severity
- 9.1 Critical severity
- 7.8 High severity
- 8.1 High severity
- 7.1 High severity
- 8.1 High severity
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