Security readout for executives and security teams
Plain-English summary
CVE-2025-9784 is a denial-of-service flaw in Undertow’s HTTP/2 handling. A remote unauthenticated client can send malformed requests that make the server spend excessive work resetting streams, potentially degrading or interrupting applications using affected Red Hat JBoss EAP and Undertow packages.
Executive priority
Treat as a high-priority availability risk for business-critical Java application platforms. It does not expose data directly, but it can interrupt service. Prioritize patching externally reachable EAP or Undertow deployments and confirm whether HTTP/2 is exposed.
Technical view
The issue is described as the MadeYouReset attack: malformed HTTP/2 client requests trigger server-side stream resets without abuse counters. It is not a protocol flaw, but an implementation weakness tied to resource handling and uncontrolled resource allocation. CVSS is 7.5 because availability impact is high and exploitation is network reachable with low complexity.
Likely exposure
Exposure is most likely where affected Red Hat JBoss Enterprise Application Platform or Undertow packages serve HTTP/2 traffic, especially internet-facing or partner-facing applications. The bundle lists multiple EAP 7.1, 7.3, 7.4 ELS, and EAP 8 package streams as affected; product/version validation is required.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The vulnerability is still operationally important because denial-of-service attacks can be launched remotely without authentication if affected HTTP/2 services are reachable.
Researcher notes
Evidence supports a remote HTTP/2 denial-of-service weakness caused by server-side stream abort behavior and missing abuse counting. The bundle names vendor advisories, Red Hat Bugzilla, Undertow PR 1778, release 2.2.38.Final, and CERT VU#767506, but detailed exploit status is not established here.
Mitigation direction
- Apply the relevant Red Hat RHSA update for each affected product stream.
- Check Red Hat CVE guidance before selecting fixed package versions.
- Review Undertow upstream release and pull request references for implementation context.
- Limit external exposure of affected HTTP/2 services where business permits.
- Prioritize internet-facing JBoss EAP and Undertow deployments first.
Validation and detection
- Inventory JBoss EAP, WildFly, and Undertow package versions across environments.
- Compare installed packages against the affected CPEs and versions in Red Hat advisories.
- Identify services accepting HTTP/2 traffic from untrusted networks.
- Confirm updated packages are deployed after applying vendor errata.
- Monitor availability metrics and HTTP/2 reset anomalies for affected services.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-404: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-770: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2025-9784 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6redhatVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- Source timelineredhat
Reported to Red Hat.
- Source timelineredhat
Made public.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- RHSA-2025:23143CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0383CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0384CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:0386CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:33371CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:33372CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:3889CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:3891CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:3892CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:4915CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:4916CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:4917CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- RHSA-2026:4924CVE reference, redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2025-9784CVE reference, redhat · vdb-entry, x_refsource_REDHAT
- RHBZ#2392306CVE reference, redhat · issue-tracking, x_refsource_REDHAT
- https://github.com/undertow-io/undertow/pull/1778CVE reference, redhat
- https://github.com/undertow-io/undertow/releases/tag/2.2.38.FinalCVE reference, redhat
- https://issues.redhat.com/browse/UNDERTOW-2598CVE reference, redhat
- https://kb.cert.org/vuls/id/767506CVE reference, redhat
- https://www.kb.cert.org/vuls/id/767506CVE reference, CVE
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Resource Shutdown or Release
Improper Resource Shutdown or Release represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.
Allocation of Resources Without Limits or Throttling
Allocation of Resources Without Limits or Throttling represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.