CVE-2026-43512 | Apache Tomcat: Digest authenticator will authenticate any unknown user

DEPRECATED: Authentication Bypass Issues vulnerability in digest authentication in Apache Tomcat. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.21, from 10.1.0-M1 through 10.1.54, from 9.0.0.M1 through 9.0.117, from 8.5.0 through 8.5.100, from before 7.0.0. Older unsupported versions any also be affect Users are recommended to upgrade to version 11.0.22, 10.1.55 or 9.0.118 which fix the issue.

Published: 2026-05-12 Last update: 2026-05-15 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-43512 is rated Moderate Risk (48.3/100): CVSS Critical severity, with low exploitation likelihood (EPSS 0.09%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-43512

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-15 0.04% 0.09% +0.05%
2 2026-05-13 — 0.04% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-43512

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-43512

GitHub Security Advisory for CVE-2026-43512

GHSA-h6fc-48rj-7qqh · Severity: critical · Ecosystem: maven — Apache Tomcat - Digest authenticator will authenticate any unknown user

OS Trackers for CVE-2026-43512

vendor priority summary link
debian not yet assigned CVE-2026-43512 not yet assigned priority: Debian including 3 source packages (tomcat10, tomcat11, tomcat9), 12 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 7, open 5. https://security-tracker.debian.org/tracker/CVE-2026-43512
suse high — https://www.suse.com/security/cve/CVE-2026-43512/
ubuntu medium CVE-2026-43512 medium priority: Ubuntu including 6 source packages (tomcat10, tomcat11, tomcat6, tomcat7, tomcat8, tomcat9), 37 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): needs-triage 19, DNE 15, ignored 3. https://ubuntu.com/security/CVE-2026-43512

Affected software / configurations for CVE-2026-43512

Vendor Product Version Raw CPE
apache tomcat >= 7.0.0, <= 7.0.109 cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
apache tomcat >= 8.5.0, <= 8.5.100 cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
apache tomcat >= 9.0.0, < 9.0.118 cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
apache tomcat >= 10.1.0, < 10.1.55 cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*
apache tomcat >= 11.0.0, < 11.0.22 cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*

References for CVE-2026-43512

cvelogic Threat Intelligence