CVE-2026-44631: apache software foundation apache http server Buffer Underflow
CVSS: 9.8v3.1CriticalAnalyzed
AliasesALPINE-CVE-2026-44631UBUNTU-CVE-2026-44631DEBIAN-CVE-2026-44631
Published 08-06-2026Last modified 08-06-2026
Vulnerability summary
CVE-2026-44631 is a critical (CVSS 9.8) Buffer Underflow vulnerability in apache software foundation apache http server. EPSS estimates a 0.75% chance of exploitation in the next 30 days, higher than 53.9% of scored vulnerabilities.
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)EPSS score
0.75%
0%100%
Low · +0.24 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 18 · Related 8Timeline
- 08-06-2026PublishedVulnerability first disclosed.
- 08-06-2026Last modifiedVulnerability information updated.
Description
Buffer Underwrite vulnerability in Apache HTTP Server on crafted regular expressions in the configuration. This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67. Users are recommended to upgrade to version 2.4.68, which fixes the issue.
CVSS metrics
5 scores · 5 sources · 1 versionCritical 9.8Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSourcesAll 5 agree
- OSV · AlpineEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVDNIST9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.75%
Chance of exploitation in the next 30 days
Percentile
54%
Versus all other CVEs
30-day change
+0.24 pp
From 0.50% on 18-09-2026
18-09-202618-10-2026
EPSS score0.75%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Alpine1 product
- apache2< 2.4.68-r0
Apache1 product
- http_server≥ 2.4.0, < 2.4.68
Apache software foundation1 product
- apache http server≥ 2.4.0, ≤ 2.4.67
Debian1 product
- apache2< 2.4.68-1~deb12u1 | < 2.4.68-1~deb13u1 | < 2.4.68-1
Ubuntu1 product
- apache2< 2.4.18-2ubuntu3.17+esm19 | < 2.4.29-1ubuntu4.27+esm10 | < 2.4.41-4ubuntu3.23+esm5 | < 2.4.52-1ubuntu4.23 | < 2.4.58-1ubuntu8.15 | All versions (No fix recorded) | < 2.4.66-2ubuntu2.4
5 vendors · 5 products
