Apache Tomcat up to 11.0.26/10.1.60/9.0.122 HTTP 2 Processing/Asynchronous Servlets race condition

CVSS Meta Temp Score
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CTI Interest Score
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5.1$0-$5k0.38

Summaryinfo

A vulnerability identified as problematic has been detected in Apache Tomcat up to 11.0.26/10.1.60/9.0.122. Affected is an unknown function of the component HTTP 2 Processing/Asynchronous Servlets. The manipulation leads to race condition. This vulnerability is referenced as CVE-2026-101356. Remote exploitation of the attack is possible. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Apache Tomcat up to 11.0.26/10.1.60/9.0.122. This issue affects some unknown functionality of the component HTTP 2 Processing/Asynchronous Servlets. The manipulation with an unknown input leads to a race condition vulnerability. Using CWE to declare the problem leads to CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. Impacted is confidentiality. The summary by CVE is:

Incorrect object recycling and re-use vulnerability in Apache Tomcat affecting HTTP/2 processing of asynchronous servlets can trigger request and/or response mix-up between users. This issue affects Apache Tomcat: from 11.0.22 through 11.0.26, from 10.1.55 through 10.1.60, from 9.0.118 through 9.0.122. Users are recommended to upgrade to version 11.0.27, 10.1.61 or 9.0.123, which fixes the issue.

It is possible to read the advisory at lists.apache.org. The identification of this vulnerability is CVE-2026-101356 since 09/28/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/20/2026).

Upgrading to version 11.0.27, 10.1.61 or 9.0.123 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Race condition
CWE: CWE-362
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Tomcat 11.0.27/10.1.61/9.0.123

Timelineinfo

09/28/2026 CVE reserved
10/20/2026 +22 days Advisory disclosed
10/20/2026 +0 days VulDB entry created
10/20/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: apache.org

Advisory: lists.apache.org
Status: Confirmed

CVE: CVE-2026-101356 (🔒)
GCVE (CVE): GCVE-0-2026-101356
GCVE (VulDB): GCVE-100-422795

Entryinfo

Created: 10/20/2026 16:08
Changes: 10/20/2026 16:08 (55)
Complete: 🔍
Cache ID: 216::103

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