# CVE-2026-43958: Rrdtool: rrdtool: stack buffer overflow allows local code execution or denial of service > A local attacker can exploit a stack buffer overflow in rrdcached to execute arbitrary code or crash the service, affecting Linux systems using rrdtool. - **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Local or same network only - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 1 Jun 2026 - **Updated:** 28 Sep 2026 - **Also known as:** ALSA-2026:33731, ALSA-2026:34155, ALSA-2026:34156, AZL-89478, CLSA-2026-1783688499, CLSA-2026-1783688821, CLSA-2026-1783688923, CLSA-2026-1784070663, CLSA-2026-1784294795, CLSA-2026-1787666659, CLSA-2026-1787732471, DEBIAN-CVE-2026-43958, GHSA-pgh2-hfvj-4q69, RHSA-2026:33731, RHSA-2026:34155, RHSA-2026:34156, RHSA-2026:68702, RHSA-2026:71600, RHSA-2026:72277, RHSA-2026:72278, RLSA-2026:33731, RLSA-2026:34155, RLSA-2026:34156, SUSE-SU-2026:23119-1, SUSE-SU-2026:23141-1, SUSE-SU-2026:3449-1, SUSE-SU-2026:3468-1, UBUNTU-CVE-2026-43958, openSUSE-SU-2026:11430-1, openSUSE-SU-2026:21525-1 ## What is CVE-2026-43958? CVE-2026-43958 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 1 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim. ### Official description A flaw was found in rrdcached, a component of rrdtool. A local attacker with access to a rrdcached socket can exploit a stack-based buffer overflow by sending an oversized CREATE request. This vulnerability can lead to a denial of service by crashing the daemon or potentially allow for arbitrary code execution, impacting the integrity and confidentiality of data. Weakness: CWE-121 (Stack-based Buffer Overflow) ## Which versions are affected by CVE-2026-43958? | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `python3-rrdtool` | AlmaLinux:10 | All versions | 1.8.0-21.el10_2 | | `rrdtool` | AlmaLinux:10 | All versions | 1.8.0-21.el10_2 | | `rrdtool-devel` | AlmaLinux:10 | All versions | 1.8.0-21.el10_2 | | `rrdtool-doc` | AlmaLinux:10 | All versions | 1.8.0-21.el10_2 | | `rrdtool-lua` | AlmaLinux:10 | All versions | 1.8.0-21.el10_2 | | `rrdtool-perl` | AlmaLinux:10 | All versions | 1.8.0-21.el10_2 | | `rrdtool-ruby` | AlmaLinux:10 | All versions | 1.8.0-21.el10_2 | | `rrdtool-tcl` | AlmaLinux:10 | All versions | 1.8.0-21.el10_2 | | `python3-rrdtool` | AlmaLinux:8 | All versions | 1.7.0-17.el8_10 | | `rrdtool` | AlmaLinux:8 | All versions | 1.7.0-17.el8_10 | | `rrdtool-devel` | AlmaLinux:8 | All versions | 1.7.0-17.el8_10 | | `rrdtool-doc` | AlmaLinux:8 | All versions | 1.7.0-17.el8_10 | | `rrdtool-lua` | AlmaLinux:8 | All versions | 1.7.0-17.el8_10 | | `rrdtool-perl` | AlmaLinux:8 | All versions | 1.7.0-17.el8_10 | | `rrdtool-ruby` | AlmaLinux:8 | All versions | 1.7.0-17.el8_10 | | `rrdtool-tcl` | AlmaLinux:8 | All versions | 1.7.0-17.el8_10 | | `python3-rrdtool` | AlmaLinux:9 | All versions | 1.7.2-22.el9_8 | | `rrdtool` | AlmaLinux:9 | All versions | 1.7.2-22.el9_8 | | `rrdtool-devel` | AlmaLinux:9 | All versions | 1.7.2-22.el9_8 | | `rrdtool-doc` | AlmaLinux:9 | All versions | 1.7.2-22.el9_8 | | `rrdtool-lua` | AlmaLinux:9 | All versions | 1.7.2-22.el9_8 | | `rrdtool-perl` | AlmaLinux:9 | All versions | 1.7.2-22.el9_8 | | `rrdtool-ruby` | AlmaLinux:9 | All versions | 1.7.2-22.el9_8 | | `rrdtool-tcl` | AlmaLinux:9 | All versions | 1.7.2-22.el9_8 | | `python3-rrdtool` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `python3-rrdtool-debuginfo` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-debuginfo` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-debugsource` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-devel` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-doc` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-lua` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-lua-debuginfo` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-perl` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-perl-debuginfo` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-ruby` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-ruby-debuginfo` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-tcl` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `rrdtool-tcl-debuginfo` | Red Hat:enterprise_linux:10.2 | All versions | 0:1.8.0-21.el10_2 | | `python3-rrdtool-debuginfo` | Red Hat:enterprise_linux:8::appstream | All versions | 0:1.7.0-17.el8_10 | ## How do I fix CVE-2026-43958? Apply the vendor's patch. ## Is CVE-2026-43958 being exploited? There is no known exploitation of CVE-2026-43958 in the wild and no public exploit code. ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-43958 and fix it if it is affected. What it is: CVE-2026-43958 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 1 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-43958 in the wild and no public exploit code. Affected product: Red Hat Enterprise Linux 10. 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-2026-43958/ (Markdown: https://insights.sbomify.com/CVE-2026-43958/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43958 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43958 - OSV: https://osv.dev/vulnerability/CVE-2026-43958 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-43958/ Summaries are generated and may contain mistakes; the official description above is the record.