CVE-2026-34486 — Apache Tomcat Missing Encryption of Sensitive Data Vulnerability
Missing Encryption of Sensitive Data vulnerability in Apache Tomcat due to the fix for CVE-2026-29146 allowing the bypass of the EncryptInterceptor. This issue affects Apache Tomcat: 11.0.20, 10.1.53, 9.0.116. Users are recommended to upgrade to version 11.0.21, 10.1.54 or 9.0.117, which fix the issue.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Confirmed exploitation (CISA KEV)+35
- Public exploit/PoC (nuclei, github)+10
- EPSS 6.6% (30-day exploitation probability)+14
- Technical severity (high)+6
- Automatable exploitation (SSVC)+3
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented mitigation — www.vicarius.io (NIST National Vulnerability Database)
- Maven Org.apache.tomcat:tomcat: fixed in version 11.0.21 — github.com (GitHub Security Advisories)
- Maven Org.apache.tomcat:tomcat: fixed in version 10.1.54 — github.com (GitHub Security Advisories)
- Maven Org.apache.tomcat:tomcat: fixed in version 9.0.117 — github.com (GitHub Security Advisories)
- Maven Org.apache.tomcat:tomcat-tribes: fixed in version 11.0.21 — github.com (GitHub Security Advisories)
- Maven Org.apache.tomcat:tomcat-tribes: fixed in version 10.1.54 — github.com (GitHub Security Advisories)
- Maven Org.apache.tomcat:tomcat-tribes: fixed in version 9.0.117 — github.com (GitHub Security Advisories)
CISA required action CISA
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
US federal deadline: Aug 7, 2026 — passed 69 day(s) ago
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Apache Software Foundation Tomcat, Red Hat Enterprise Linux, Red Hat Enterprise Linux Els…).
- Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- Apply the fixed version or the patch documented under Remediation.
- EPSS ahead of 94% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes matching the vulnerability class (cryptography), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Apache Software Foundation | Tomcat | version 9.0.116version 10.1.53version 11.0.20 | Vulnerable | NIST National Vulnerability Database |
| Apache Software Foundation | Tomcat | version 11.0.20version 10.1.53version 9.0.116 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Red Hat | Enterprise Linux | version 9.0version 10.0version 8.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux Els | version 7.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux Eus | version 10.0 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux Tus | version 8.8 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Enterprise Linux Update Services For Sap Solutions | version 8.8version 9.2version 9.4version 9.6 | Vulnerable | NIST National Vulnerability Database |
| Red Hat | Jboss Web Server | version 7.0.0 | Vulnerable | NIST National Vulnerability Database |
| Maven | Org.apache.tomcat:tomcat | version 11.0.20version 10.1.53version 9.0.116 | Vulnerable | GitHub Security Advisories |
| Maven | Org.apache.tomcat:tomcat-tribes | version 11.0.20version 10.1.53version 9.0.116 | Vulnerable | GitHub Security Advisories |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database |
| 7.5 | CVSS 3.1 | High | 3.9 | 3.6 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c via NIST National Vulnerability Database |
| 7.5 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.5 | CVSS 3.1 | High | — | — | CISA-ADP via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N (score shown at the top: 134c704f-9b21-4f2e-91b3-4a467353bcc0) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CISA KEV details CISA
CISA lists a CVE once it has evidence of exploitation against real targets.
CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.
Public exploits, PoCs and detection templates
Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.
- EncryptInterceptor fail-open bypass in Apache Tomcat Tribes clustering leading to unauthenticated RCE via Java deserialization. ★ 70 May 11, 2026
- CVE-2026-34486 Apache Tomcat EncryptInterceptor 绕过漏洞复现（使用GLM5.1复现完成） ★ 12 Apr 15, 2026
- Apache Tomcat EncryptInterceptor Bypass → Unauthenticated RCE (CVE-2026-34486) ★ 10 Apr 15, 2026
- CVE Reproduction: cve-2026-34486-tomcat_encrypt_bypass_reproduction ★ 0 Jul 23, 2026
- EncryptInterceptor fail-open bypass in Apache Tomcat Tribes clustering leading to unauthenticated RCE via Java deserialization. ★ 0 Aug 19, 2026
Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.
EPSS over time FIRST
Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 6.56%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Check TLS negotiations and unexpected certificates in the component’s traffic.
- Hunt retroactively in logs from before Aug 4, 2026 (KEV listing): exploitation may have started earlier.
Timeline
What happened to this CVE, newest first.
- 2026
- Fix documented
- Affected products added · maven/org.apache.tomcat:tomcat, maven/org.apache.tomcat:tomcat-tribes
- Affected products added · apache software foundation/apache tomcat
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · apache/tomcat, redhat/jboss web server, redhat/enterprise linux, redhat/enterprise linux els, redhat/enterprise linux eu
- CVSS changed · 7.5
- Source status changed · → Analyzed
- Added to CISA KEV (detected)
- Record created in this database
- Added to CISA KEV catalog
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 13, 2026 – Oct 13, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
30 on the record
- lists.apache.org/thread/9510k5p5zdvt9pkkgtyp85mvwxo2qrly
- www.vicarius.io/vsociety/posts/cve-2026-34486-mitigation-script-rce-on-apache-tomcat
- www.cisa.gov/known-exploited-vulnerabilities-catalog
- socradar.io/blog/snowlight-government-chinese-campaign/
- access.redhat.com/errata/RHSA-2026:37136
- access.redhat.com/errata/RHSA-2026:38505
- access.redhat.com/errata/RHSA-2026:36877
- access.redhat.com/errata/RHSA-2026:36879
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34486.json
- www.vicarius.io/vsociety/posts/cve-2026-34486-detection-script-rce-on-apache-tomcat
- access.redhat.com/errata/RHSA-2026:36787
- nvd.nist.gov/vuln/detail/CVE-2026-34486
- access.redhat.com/errata/RHSA-2026:36790
- github.com/apache/tomcat/commit/1fab40ccc752e22639eccfe290d5624afad7eccd
- github.com/apache/tomcat/commit/55f3eb9148233054fccfdf761141c6894a050be1
- github.com/advisories/GHSA-69r9-qgr7-g2wj
- www.herodevs.com/vulnerability-directory/cve-2026-34486
- access.redhat.com/errata/RHSA-2026:36876
- bugzilla.redhat.com/show_bug.cgi
- tomcat.apache.org/security-9.html
- access.redhat.com/errata/RHSA-2026:37137
- tomcat.apache.org/security-11.html
- access.redhat.com/errata/RHSA-2026:36788
- access.redhat.com/security/cve/CVE-2026-34486
- tomcat.apache.org/security-10.html
- access.redhat.com/errata/RHSA-2026:36789
- access.redhat.com/errata/RHSA-2026:36878
- github.com/apache/tomcat/commit/776e12b3e2b0b4507b8a3b62c187ceb0b74bf418
- access.redhat.com/errata/RHSA-2026:39188
- access.redhat.com/errata/RHSA-2026:39189
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2026-104045 Sssd: sssd: denial of service via race condition in autofs responder 8d
- Medium CVE-2026-104046 Sssd: sssd: denial of service via incomplete identity provider authentication requests 8d
- High CVE-2026-104048 Sssd: sssd: authorization bypass via cross-domain username collision in hbac evaluation 8d
- Medium CVE-2026-104047 Sssd: sssd: information disclosure via query injection in entra id lookups 8d
- High CVE-2026-102558 Libsoup: libsoup: heap buffer overflow during websocket receive-buffer growth 15d
- High CVE-2026-102555 Libsoup: libsoup: heap buffer overflow via uninitialized length in data-uri base64 decoding 15d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-34486 is "Apache Tomcat Missing Encryption of Sensitive Data Vulnerability", rated High. It affects Tomcat (Apache Software Foundation); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 7.5 describes technical severity. EPSS 6.56% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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