CVE-2025-48989Public exploitNetwork attack vector

Unauthenticated service interruption via uncounted server-sent HTTP/2 resets

Published Aug 13, 2025 · Updated May 12, 2026

HTTP/2 resource exhaustion in affected Apache Tomcat releases allows remote attackers to interrupt service using malformed control frames. The HTTP/2 upgrade handlers failed to charge server-sent RST_STREAM frames to the connection overhead counter, so reset streams stopped counting toward concurrency limits while their requests kept consuming backend resources. The attack requires a network-reachable connector with HTTP/2 enabled and can overload CPU or exhaust memory, but it grants no reported data access or modification.

CVSS severity7.5
High
EPSS probability3.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

HTTP/2 resource exhaustion in affected Apache Tomcat releases allows remote attackers to interrupt service using malformed control frames. The HTTP/2 upgrade handlers failed to charge server-sent RST_STREAM frames to the connection overhead counter, so reset streams stopped counting toward concurrency limits while their requests kept consuming backend resources. The attack requires a network-reachable connector with HTTP/2 enabled and can overload CPU or exhaust memory, but it grants no reported data access or modification.

The record

CVE
CVE-2025-48989
Published
Aug 13, 2025
Updated
May 12, 2026
Vendor
The Apache Software Foundation
Product
Apache Tomcat
Classifications
CWE-404, CAPEC-125, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 13, 2025CVE publishedPublication date reported by the CVE source.
  2. May 12, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=10.1.0-M1 <=10.1.43
  2. Affected versionversion=11.0.0-M1 <=11.0.9
  3. Affected versionversion=9.0.0.M1 <=9.0.107

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Apache Software Foundation · Apache Tomcatversion=10.1.0-M1 <=10.1.43; version=11.0.0-M1 <=11.0.9; version=9.0.0.M1 <=9.0.107
Siemens · SIMATIC CN 4100version=0 <V5.0

Published CVSS scores

7.5CISA ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-404Improper Resource Shutdown or Release
CAPEC-125Flooding
T1499.003Application Exhaustion Flood

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo