Linux: Out-of-bounds Read
CVE-2026-43112 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 a2ba20c17de8eb028f96b1d85f119d3d25655bd9, fbced33599653471b4581dfe1abc7b467031f126, 5d4fe469fe7dbff7d874c196bb680a82f2625d95 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 0.35% 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 a2ba20c17de8eb028f96b1d85f119d3d25655bd9 or fbced33599653471b4581dfe1abc7b467031f126 or 5d4fe469fe7dbff7d874c196bb680a82f2625d95 or 2d29214448ec0f4e7e18bb1c14dd4a6c07f1c439, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.136 or 6.12.83 or 6.18.24 or 6.19.14, 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 | c63433a09d6ae4c226fcbc66da4c58fc189fd746 up to, but not including, a2ba20c17de8eb028f96b1d85f119d3d25655bd9; a31080899d5fdafcccf7f39dd214a814a2c82626 up to, but not including, fbced33599653471b4581dfe1abc7b467031f126; a31080899d5fdafcccf7f39dd214a814a2c82626 up to, but not including, 5d4fe469fe7dbff7d874c196bb680a82f2625d95; a31080899d5fdafcccf7f39dd214a814a2c82626 up to, but not including, 2d29214448ec0f4e7e18bb1c14dd4a6c07f1c439; a31080899d5fdafcccf7f39dd214a814a2c82626 up to, but not including, 86f9c23e0814cfdffda9eedf0c591c51ba209010; a31080899d5fdafcccf7f39dd214a814a2c82626 up to, but not including, 49b1ce6d7cfb6c5a49f68bf5ccfcfb6ba14e63c3; a31080899d5fdafcccf7f39dd214a814a2c82626 up to, but not including, 78ec5bf2f589ec7fd8f169394bfeca541b077317; 5.15.11 up to, but not including, 5.15.209; and 1 more ranges | a2ba20c17de8eb028f96b1d85f119d3d25655bd9, fbced33599653471b4581dfe1abc7b467031f126, 5d4fe469fe7dbff7d874c196bb680a82f2625d95, 2d29214448ec0f4e7e18bb1c14dd4a6c07f1c439, 86f9c23e0814cfdffda9eedf0c591c51ba209010, 49b1ce6d7cfb6c5a49f68bf5ccfcfb6ba14e63c3 |
| Red Hat | Red Hat Enterprise Linux 10 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 10.0 Extended Update Support | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8.8 Telecommunications Update Service | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9.4 Update Services for SAP Solutions | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.12 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.13 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.14 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.16 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.17 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.18 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.19 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.20 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.21 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4.22 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 6 | Not specified in the record | Not stated |
| Red Hat | Red Hat Enterprise Linux 7 | Not specified in the record | Not stated |
| Red Hat | Red Hat OpenShift Container Platform 4 | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE; 2 further products are omitted here. 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.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | CNA |
| CVSS 3.1 | 8.1 | High | CNA |
Official description
In the Linux kernel, the following vulnerability has been resolved: fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath When cifs_sanitize_prepath is called with an empty string or a string containing only delimiters (e.g., "/"), the current logic attempts to check *(cursor2 - 1) before cursor2 has advanced. This results in an out-of-bounds read. This patch adds an early exit check after stripping prepended delimiters. If no path content remains, the function returns NULL. The bug was identified via manual audit and verified using a standalone test case compiled with AddressSanitizer, which triggered a SEGV on affected inputs.
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
- git.kernel.org/stable/c/2d29214448ec0f4e7e18bb1c14dd4a6c07f1c439
- git.kernel.org/stable/c/49b1ce6d7cfb6c5a49f68bf5ccfcfb6ba14e63c3
- git.kernel.org/stable/c/5d4fe469fe7dbff7d874c196bb680a82f2625d95
- git.kernel.org/stable/c/78ec5bf2f589ec7fd8f169394bfeca541b077317
- git.kernel.org/stable/c/86f9c23e0814cfdffda9eedf0c591c51ba209010
Other references
- git.kernel.org/stable/c/a2ba20c17de8eb028f96b1d85f119d3d25655bd9
- git.kernel.org/stable/c/fbced33599653471b4581dfe1abc7b467031f126
- access.redhat.com/errata/RHSA-2026:34911
- access.redhat.com/errata/RHSA-2026:36018
- access.redhat.com/errata/RHSA-2026:36365
- access.redhat.com/errata/RHSA-2026:36366
- access.redhat.com/errata/RHSA-2026:40764
- access.redhat.com/errata/RHSA-2026:52649
- access.redhat.com/errata/RHSA-2026:52764
- access.redhat.com/errata/RHSA-2026:53989
- access.redhat.com/errata/RHSA-2026:53990
- access.redhat.com/errata/RHSA-2026:56573
- access.redhat.com/errata/RHSA-2026:57402
- access.redhat.com/errata/RHSA-2026:57457
- access.redhat.com/errata/RHSA-2026:57543
Recent Out-of-bounds Read vulnerabilities
- 8.8 High severity
- 8.1 High severity
- 8.8 High severity
- 7.1 High severity
- 7.1 High severity
- 8.4 High severity
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