CVE-2021-26691
9.8
CRITICAL · CVSS 3.1 · EPSS 68.3% (pctl 99)
Patch early
EPSS 68.3% — above the 10% action threshold.
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
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 68.29% — more likely to be exploited than 99% of all CVEs |
| Weakness | CWE-122 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2021-06-10 |
| Last modified | 2026-06-17 |
Affected (8)
| Vendor | Product |
|---|---|
| apache | http server |
| debian | debian linux |
| fedoraproject | fedora |
| netapp | cloud backup |
| oracle | enterprise manager ops center |
| oracle | instantis enterprisetrack |
| oracle | secure backup |
| oracle | zfs storage appliance kit |
References
- http://httpd.apache.org/security/vulnerabilities_24.html
- http://www.openwall.com/lists/oss-security/2021/06/10/7
- https://lists.apache.org/thread.html/r50cae1b71f1e7421069036b213c26da7d8f47dd59874e3bd956959fe%40%3Cannounce.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r7f2b70b621651548f4b6f027552f1dd91705d7111bb5d15cda0a68dd%40%3Cdev.httpd.apache.org%3E
- https://lists.apache.org/thread.html/re026d3da9d7824bd93b9f871c0fdda978d960c7e62d8c43cba8d0bf3%40%3Ccvs.httpd.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2021/07/msg00006.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/
- https://security.gentoo.org/glsa/202107-38
- https://security.netapp.com/advisory/ntap-20210702-0001/
- https://www.debian.org/security/2021/dsa-4937
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuoct2021.html
- http://httpd.apache.org/security/vulnerabilities_24.html
- http://www.openwall.com/lists/oss-security/2021/06/10/7
- https://lists.apache.org/thread.html/r50cae1b71f1e7421069036b213c26da7d8f47dd59874e3bd956959fe%40%3Cannounce.httpd.apache.org%3E
- https://lists.apache.org/thread.html/r7f2b70b621651548f4b6f027552f1dd91705d7111bb5d15cda0a68dd%40%3Cdev.httpd.apache.org%3E
- https://lists.apache.org/thread.html/re026d3da9d7824bd93b9f871c0fdda978d960c7e62d8c43cba8d0bf3%40%3Ccvs.httpd.apache.org%3E
- https://lists.debian.org/debian-lts-announce/2021/07/msg00006.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/
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