Mod_qos: undersized connection-monitor scratch array permits heap buffer overflow

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

A flaw was found in mod_qos. An unauthenticated remote attacker can cause a Denial of Service (DoS) by maintaining numerous concurrent low-rate connections to a target server. When connection rate monitoring is active, the module fails to verify array boundaries when recording client IP addresses, allowing more connection records to be added than the allocated buffer can hold. This issue leads to heap memory corruption, which can crash the web server process.

Source published

22 Oct 2026 06:37:04 UTC

Source modified

26 Oct 2026 19:38:30 UTC

Observed here

26 Oct 2026 20:35:31 UTC

Source terms

CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 3.1 · 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H