# CVE-2026-43112: fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath > An out-of-bounds read in the Linux kernel SMB client allows attackers to cause a system crash via crafted path inputs. - **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** A user has to click or open something - **Fix available:** Yes - **Published:** 6 May 2026 - **Updated:** 19 Oct 2026 - **Also known as:** ALSA-2026:36365, ALSA-2026:36366, BELL-CVE-2026-43112, DEBIAN-CVE-2026-43112, GHSA-24h4-22f3-65qc, RHSA-2026:36365, RHSA-2026:36366, RHSA-2026:62558, RHSA-2026:62637, RLSA-2026:36365, RLSA-2026:36366, ROOT-OS-DEBIAN-11-CVE-2026-43112, ROOT-OS-DEBIAN-12-CVE-2026-43112, ROOT-OS-UBUNTU-2204-CVE-2026-43112, ROOT-OS-UBUNTU-2404-CVE-2026-43112, UBUNTU-CVE-2026-43112 ## What is CVE-2026-43112? CVE-2026-43112 is a high-severity memory corruption vulnerability in Linux kernel, published on 6 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. ### 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. Weakness: CWE-125 (Out-of-bounds Read) ## Which versions are affected by CVE-2026-43112? It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `bpftool` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-abi-stablelists` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-core` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-cross-headers` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-debug` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-debug-core` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-debug-devel` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-debug-modules` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-debug-modules-extra` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-devel` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-doc` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-headers` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-modules` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-modules-extra` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-rt` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.rt7.482.el8_10 | | `kernel-rt-core` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.rt7.482.el8_10 | | `kernel-rt-debug` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.rt7.482.el8_10 | | `kernel-rt-debug-core` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.rt7.482.el8_10 | | `kernel-rt-debug-devel` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.rt7.482.el8_10 | | `kernel-rt-debug-modules` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.rt7.482.el8_10 | | `kernel-rt-debug-modules-extra` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.rt7.482.el8_10 | | `kernel-rt-devel` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.rt7.482.el8_10 | | `kernel-rt-modules` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.rt7.482.el8_10 | | `kernel-rt-modules-extra` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.rt7.482.el8_10 | | `kernel-tools` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-tools-libs` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-tools-libs-devel` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-zfcpdump` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-zfcpdump-core` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-zfcpdump-devel` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-zfcpdump-modules` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `kernel-zfcpdump-modules-extra` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `perf` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `python3-perf` | AlmaLinux:8 | All versions | 4.18.0-553.141.1.el8_10 | | `bpftool` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-553.141.1.el8_10 | | `bpftool-debuginfo` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-553.141.1.el8_10 | | `kernel` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-553.141.1.el8_10 | | `kernel-abi-stablelists` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-553.141.1.el8_10 | | `kernel-core` | Red Hat:enterprise_linux:8::baseos | All versions | 0:4.18.0-553.141.1.el8_10 | Products: Linux kernel. ## How do I fix CVE-2026-43112? Apply the vendor's patch. ## Is CVE-2026-43112 being exploited? There is no known exploitation of CVE-2026-43112 in the wild and no public exploit code. ## Other vulnerabilities in Linux kernel - [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild) - [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild) - [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild) - [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild) - [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-43112 and fix it if it is affected. What it is: CVE-2026-43112 is a high-severity memory corruption vulnerability in Linux kernel, published on 6 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link. Exploitation: There is no known exploitation of CVE-2026-43112 in the wild and no public exploit code. Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-43112/ (Markdown: https://insights.sbomify.com/CVE-2026-43112/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43112 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43112 - OSV: https://osv.dev/vulnerability/CVE-2026-43112 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-43112/ Summaries are generated and may contain mistakes; the official description above is the record.