HighCVE-2025-8671

    SUSE Linux Enterprise Module for Development Tools: Denial of Service (CVE-2025-8671)

    Published Sources: BSI, CVE.org, OSV, Debian

    What is affected, what to do

    A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting.

    An exploit is publicly available. Update SUSE Linux Enterprise Module for Development Tools to version 15-SP5.

    Affected
    • SUSE Linux Enterprise Module for Development Tools lt 15 SP2..15-SP5
    • SUSE Linux Enterprise High Performance Computing (HPC) gte 15..*
    • Varnish Enterprise lte 6.0.x..6.0.14r4
    • Varnish Cache lte 6.0LTS..6.014
    • Varnish Cache lte 5.x..7.71
    • Fastly H20 eq 579ecfa..579ecfa
    • Wind River Linux gte LTS22..*
    • SUSE Linux Enterprise Desktop gte 15 SP6..*
    • SUSE Linux Enterprise High Performance Computing gte 15 SP3..*
    • SUSE Linux Enterprise Module for Dev Tools gte 15 SP3..*
    • SUSE Linux Enterprise Module for Package Hub gte 15 SP5..*
    • SUSE Linux Enterprise Server gte 12 SP5..*
    • SUSE Linux Enterprise Server for SAP Applications gte 15 SP6..*
    • SUSE Manager Server eq 4.3..4.3
    • SUSE Manager Server LTS eq 4.3..4.3
    • SUSE Manager Proxy eq 4.3..4.3
    • SUSE Manager Retail Branch Server eq 4.3..4.3
    • SUSE Linux openSUSE Leap eq 15.6..15.6
    Fixed in
    • SUSE Linux Enterprise Module for Development Tools 15-SP5

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    7.5

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    7.5

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: BSI, CVE.org, OSV, Debian

    3.6 %

    EPSS score

    Moderate — model estimates 1-10% exploitation likelihood.

    Source: FIRST EPSS, percentile 89.5

    Show all metrics
    Severity
    High
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    111.91 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    PoC (publicly reported)
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    7.5 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    7.5
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    3.6 %
    Moderate — model estimates 1-10% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    89.5
    Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CISA assessment (SSVC)
    Exploitation: proof of concept · automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 13 August 2025
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-404

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    A mismatch caused by client-triggered server-sent stream resets between HTTP/2 specifications and the internal architectures of some HTTP/2 implementations may result in excessive server resource consumption leading to denial-of-service (DoS). By opening streams and then rapidly triggering the server to reset them—using malformed frames or flow control errors—an attacker can exploit incorrect stream accounting. Streams reset by the server are considered closed at the protocol level, even though backend processing continues. This allows a client to cause the server to handle an unbounded number of concurrent streams on a single connection. This CVE will be updated as affected product details are released.

    Source: BSI WID Portal, BSI CSAF, NVD (NIST), cvelistv5, OSV (Open Source Vulnerabilities), CVE.org (MITRE), Debian Security Advisories

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    FastlyH20
    • 579ecfa
    • —
    SUSE LinuxEnterprise Desktop
    • ≥ 15 SP6
    • —
    SUSE LinuxEnterprise High Performance Computing
    • ≥ 15 SP3
    • —
    SUSE LinuxEnterprise High Performance Computing (HPC)
    • ≥ 15
    • —
    SUSE LinuxEnterprise Module for Dev Tools
    • ≥ 15 SP3
    • —
    SUSE LinuxEnterprise Module for Development Tools
    • 15 SP2 – < 15-SP5
    • 15-SP5
    SUSE LinuxEnterprise Module for Package Hub
    • ≥ 15 SP5
    • —
    SUSE LinuxEnterprise Server
    • ≥ 12 SP5
    • —
    SUSE LinuxEnterprise Server for SAP Applications
    • ≥ 15 SP6
    • —
    SUSE LinuxopenSUSE Leap
    • 15.6
    • —
    SUSE LinuxSUSE Manager Proxy
    • 4.3
    • —
    SUSE LinuxSUSE Manager Retail Branch Server
    • 4.3
    • —
    SUSE LinuxSUSE Manager Server
    • 4.3
    • —
    SUSE LinuxSUSE Manager Server LTS
    • 4.3
    • —
    Varnish SoftwareVarnish Cache
    • 5.x – ≤ 7.71
    • 6.0LTS – ≤ 6.014
    • —
    • —
    Varnish SoftwareVarnish Enterprise
    • 6.0.x – ≤ 6.0.14r4
    • —
    Wind RiverLinux
    • ≥ LTS22
    • —
    XeroxFreeFlow Print Server
    • v7
    • v2
    • —
    • —

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianvarnishtrixie

    Weakness classes (CWE)

    • CWE-404Improper Resource Shutdown or Release

      Class

      The product does not release or incorrectly releases a resource before it is made available for re-use.

      Entry at MITRE CWE-404

    Public exploit references

    Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.

    Public exploit references
    PoC-in-GitHub (nomi-sec)MadeYouReset_Tester (opens in a new tab)github.comPoC (publicly reported)reported, not verified

    References & sources

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    Badge preview for CVE-2025-8671
    <a href="https://intel.neosec.eu/en/cve/CVE-2025-8671"><img src="https://intel.neosec.eu/badge/cve/CVE-2025-8671.svg?lang=en" alt="CVE-2025-8671 – NEOSEC Intel" height="20"></a>