CVE detail

CVE-2021-26691 — CVE-2021-26691

Published 2021-06-10 · Modified 2026-06-17 · Vendor apache · Product http_server · Source nvd

CRITICAL

severity

CVSS-derived band

9.8

CVSS v3

0–10 scale

0.6829

EPSS probability

exploitation probability, 30d

99.0%

EPSS percentile

percentile vs all CVEs

NOT LISTED

CISA KEV

known exploited catalog

Description

In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server could cause a heap overflow

Remediation

No vendor-published fix data in our corpus for this CVE. Check the references below or the vendor's PSIRT / security advisories page.

References

cvedb.io · NVD · CISA KEV · FIRST EPSS · vendor advisories (CVE Program List v5). Informational only, no warranty — verify every remediation against the vendor advisory before acting on it. This product uses data from the NVD API but is not endorsed or certified by the NVD, CISA, FIRST.org or any vendor named. CVE® is a registered trademark of The MITRE Corporation.