CVE Intelligence
Low exploit reference

CVE-2012-4534 — org/apache/tomcat/util/net/NioEndpoint.java in Apache Tomcat 6.x before 6.0.36 and 7.x…

org/apache/tomcat/util/net/NioEndpoint.java in Apache Tomcat 6.x before 6.0.36 and 7.x before 7.0.28, when the NIO connector is used in conjunction with sendfile and HTTPS, allows remote attackers to cause a denial of service (infinite loop) by terminating the connection during the reading of a response.

Published Dec 19, 2012 · Updated Oct 13, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: redhat

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 7.5% (30-day exploitation probability)+14
  • 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.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
7.45%
ahead of 94% of scored CVEs · Oct 14, 2026
Affects
Apache Software Foundation
Tomcat
CVSS base
2.6
Low · 1 source(s)

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.

Exploitation
None
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented patch — svn.apache.org (NIST National Vulnerability Database)
  • Documented patch — svn.apache.org (NIST National Vulnerability Database)

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Apache Software Foundation Tomcat).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. Apply the fixed version or the patch documented under Remediation.
  4. EPSS ahead of 94% of scored CVEs: prioritize it in the patch queue.
  5. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Apache Software Foundation Tomcat version 7.0.1version 7.0.7version 7.0.6version 7.0.5version 7.0.4-betaversion 7.0.4version 7.0.3version 7.0.2-beta
and 62 more version 7.0.2version 7.0.8version 7.0.0-betaversion 7.0.0version 6.0.35version 6.0.33version 6.0.32version 6.0.31version 6.0.30version 6.0.29version 7.0.16version 7.0.25version 7.0.23version 7.0.22version 7.0.21version 7.0.20version 7.0.19version 7.0.18version 7.0.17version 6.0.28version 7.0.15version 7.0.14version 7.0.13version 7.0.12version 7.0.11version 7.0.10version 7.0.9version 6.0.4version 6.0.8version 6.0.7-betaversion 6.0.7-alphaversion 6.0.7version 6.0.6-alphaversion 6.0.6version 6.0.5version 6.0.4-alphaversion 6.0.8-alphaversion 6.0.3version 6.0.2-betaversion 6.0.2-alphaversion 6.0.2version 6.0.1-alphaversion 6.0.1version 6.0.0-alphaversion 6.0.0version 6.0.15version 6.0.27version 6.0.26version 6.0.24version 6.0.20version 6.0.19version 6.0.18version 6.0.17version 6.0.16version 6.0version 6.0.14version 6.0.13version 6.0.12version 6.0.11version 6.0.10version 6.0.9-betaversion 6.0.9
Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
High
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
2.6 CVSS 2.0 Low 4.9 2.9 nvd@nist.gov via NIST National Vulnerability Database
AV:N/AC:H/Au:N/C:N/I:N/A:P (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-399

Other CVEs with this weakness →

EPSS over time FIRST

Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 7.45%

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).
web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

  • 2026
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 2.6
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 13, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 13, 2026 · NIST National Vulnerability Database
  • 2012
  • CVE published
    Dec 19, 2012 · redhat

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

19 on the record

Elsewhere on this site

Apache Software Foundation
every CVE for this vendor
CWE-399
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-55956 Apache Tomcat: Security constraints for default servlet ignored method Jun 29, 2026
  • CVE-2026-55276 Apache Tomcat: Logged effective web.xml is incomplete Jun 29, 2026
  • CVE-2026-55955 Apache Tomcat: EncryptInterceptor not protected against replay attacks Jun 29, 2026
  • CVE-2026-55957 Apache Tomcat: Authentication bypass with JNDIRealm and GSSAPI authenticated bind Jun 29, 2026
  • CVE-2026-50229 Apache Tomcat: XSS in number guess example Jun 29, 2026
  • CVE-2026-53404 Apache Tomcat: Bad ornext processing in RewriteValve Jun 29, 2026

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-2012-4534 is "org/apache/tomcat/util/net/NioEndpoint.java in Apache Tomcat 6.x before 6.0.36 and 7.x…", rated Low. It affects Tomcat (Apache Software Foundation); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 2.6 describes technical severity. EPSS 7.45% 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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