# CVE-2026-98454: smb: client: fix create context out-of-bounds reads > A remote attacker can trigger out-of-bounds reads in the Linux kernel SMB client by sending malformed SMB2/SMB3 create contexts, potentially leaking memory or causing a crash. - **Severity:** High 8.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 18 Oct 2026 - **Updated:** 24 Oct 2026 - **Also known as:** AZL-109107, BELL-CVE-2026-98454, DEBIAN-CVE-2026-98454, GHSA-q4c4-v5h3-5c35, UBUNTU-CVE-2026-98454 ## What is CVE-2026-98454? CVE-2026-98454 is a high-severity memory corruption vulnerability in Linux, published on 18 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description In the Linux kernel, the following vulnerability has been resolved: smb: client: fix create context out-of-bounds reads smb2_parse_contexts() validates the complete create-context area but does not limit each record to its Next field before dispatching it. A malformed chain can therefore expose bytes beyond the current context to a handler. The QFid handler also used a full response-structure cast although it only reads DiskFileId. The SMB2/SMB3 lease parsers made the same layout assumption: they read LeaseState and LeaseFlags at canonical offsets rather than at DataOffset. A valid non-canonical DataOffset could therefore yield unrelated in-bounds data, while a short DataLength was still accepted. Limit each context to its Next value, reject offsets before the context header, and reject malformed chains. Bound the name range by the current context and do not dispatch a known handler when DataLength is zero. Read the QFid DiskFileId only when the context data covers that field. Parse the lease context from DataOffset and require DataLength to match the v1 or v2 lease_context size used by ksmbd. A size mismatch skips lease parsing without failing the open. ## Which versions are affected by CVE-2026-98454? ## How do I fix CVE-2026-98454? Apply the vendor's patch. ## Is CVE-2026-98454 being exploited? There is no known exploitation of CVE-2026-98454 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-98454 and fix it if it is affected. What it is: CVE-2026-98454 is a high-severity memory corruption vulnerability in Linux, published on 18 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-98454 in the wild and no public exploit code. Affected product: Linux. 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-2026-98454/ (Markdown: https://insights.sbomify.com/CVE-2026-98454/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98454 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98454 - OSV: https://osv.dev/vulnerability/CVE-2026-98454 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-98454/ Summaries are generated and may contain mistakes; the official description above is the record.