VulnerabilityPublished 29 Oct 2026

CVE-2026-101296: tomcat security update

Affects tomcatSource GCVE Database

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Authoritative record:CVE-2026-101296· Critical 9.1

Not known to be exploited · CVSS 9.1 Critical : upgrade to 9.0.123-1.oe2403sp4 as a priority.

Data as of 29 Oct 2026, 11:18 UTC

CVSS 4.0 base score

9.1Critical

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.6% chance of exploitation in 30 days – higher than 49% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 9.0.123-1.oe2403sp4

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: Present
Privileges Required: None
User Interaction: None
Vulnerable system confidentiality: High
Vulnerable system integrity: High
Vulnerable system availability: None
Subsequent system confidentiality: None
Subsequent system integrity: None
Subsequent system availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: Present: The successful attack depends on the presence of specific deployment and execution conditions of the vulnerable system that enable the attack. These include: a race condition must be won to successfully exploit the vulnerability (the successfulness of the attack is conditioned on execution conditions that are not under full control of the attacker, or the attack may need to be launched multiple times against a single target before being successful); the attacker must inject themselves into the logical network path between the target and the resource requested by the victim (e.g. vulnerabilities requiring an on-path attacker).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: High: There is a total loss of confidentiality, resulting in all information within the Vulnerable System being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.
Vulnerable system integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the vulnerable system. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the vulnerable system.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade tomcat to 9.0.123-1.oe2403sp4.

Affected software

Product	Affected	Fixed in
openEuler 24.03-LTS-SP4tomcat`pkg:rpm/openEuler/tomcat&distro=openEuler-24.03-LTS-SP4`Other threats	Affected <9.0.123-1.oe2403sp4	Fixed in 9.0.123-1.oe2403sp4

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AI-suggested

Users should upgrade affected Apache Tomcat installations to versions 11.0.27, 10.1.61, or 9.0.123, which contain fixes for all identified vulnerabilities. No alternative mitigations or temporary workarounds are indicated. Applying these official fixes is the recommended and effective remediation.

Description

Multiple critical security vulnerabilities have been identified in Apache Tomcat versions ranging from early milestone releases through recent stable versions up to 11.0.26, 10.1.60, and 9.0.122. These include authentication bypass, request/response mix-up in HTTP/2 asynchronous servlets, failure to securely enforce FIPS mode, execution after redirect, local unauthorized access via a TOCTOU race condition in unix domain sockets, and incomplete cleanup issues causing information leaks and TLS 1.3 connection failures. Users are strongly recommended to upgrade to fixed versions 11.0.27, 10.1.61, or 9.0.123 to address these vulnerabilities.

Impact

The vulnerabilities collectively allow attackers to bypass authentication, cause request and response data mix-ups between users, fail to enforce cryptographic security modes properly, execute code after redirects, gain unauthorized local access, and leak sensitive information between requests. The CVSS score of 9.8 indicates critical severity with high impact on confidentiality, integrity, and availability. Exploitation could lead to unauthorized access, data leakage, and denial of service.

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Affected software

Description

AI analysisMachine-generated, updated 29 Oct 2026, 11:18 UTC

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