HighCVE-2025-38115

    Linux Kernel: security vulnerability (CVE-2025-38115)

    Published Last modified Sources: Debian LTS, SUSE, Debian, BSI, CVE.org, Msrc Update Guide, EUVD

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: net_sched: sch_sfq: fix a potential crash on gso_skb handling SFQ has an assumption of always being able to queue at least one packet. However, after the blamed commit, sch->q.len can be inflated by packets in sch->gso_skb, and an enqueue() on an empty SFQ qdisc can be followed by an immediate drop.

    Update Linux Kernel to version 5.4.295, Linux Kernel to version 5.10.239, Linux Kernel to version 5.15.186.

    Affected
    • Linux Kernel lt 4.16..5.4.295
    • Linux Kernel lt 5.5..5.10.239
    • Linux Kernel lt 5.11..5.15.186
    • Linux Kernel lt 5.16..6.1.142
    • Linux Kernel lt 6.2..6.6.94
    • Linux Kernel lt 6.7..6.12.34
    • Linux Kernel lt 6.13..6.15.3
    Fixed in
    • Linux Kernel 5.4.295
    • Linux Kernel 5.10.239
    • Linux Kernel 5.15.186
    • Linux Kernel 6.1.142
    • Linux Kernel 6.6.94
    • Linux Kernel 6.12.34
    • Linux Kernel 6.15.3
    • Linux Kernel 6.16

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

    Metrics

    7.8

    Priority

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

    Source: Vendor (CNA), CVSS v3

    7.8

    CVSS v3

    Severity High on the scale from 0 to 10.

    Source: Debian LTS, SUSE, Debian, BSI, CVE.org, Msrc Update Guide, EUVD

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 12.2

    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
    49.90 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
    no public PoC known
    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
    7.8 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
    7.8
    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
    0.2 %
    Low — model estimates < 1% 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
    12.2
    Elevated — this CVE ranks above at least 10% of all CVEs scored today.
    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

    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

    In the Linux kernel, the following vulnerability has been resolved: net_sched: sch_sfq: fix a potential crash on gso_skb handling SFQ has an assumption of always being able to queue at least one packet. However, after the blamed commit, sch->q.len can be inflated by packets in sch->gso_skb, and an enqueue() on an empty SFQ qdisc can be followed by an immediate drop. Fix sfq_drop() to properly clear q->tail in this situation. ip netns add lb ip link add dev to-lb type veth peer name in-lb netns lb ethtool -K to-lb tso off # force qdisc to requeue gso_skb ip netns exec lb ethtool -K in-lb gro on # enable NAPI ip link set dev to-lb up ip -netns lb link set dev in-lb up ip addr add dev to-lb 192.168.20.1/24 ip -netns lb addr add dev in-lb 192.168.20.2/24 tc qdisc replace dev to-lb root sfq limit 100 ip netns exec lb netserver netperf -H 192.168.20.2 -l 100 & netperf -H 192.168.20.2 -l 100 & netperf -H 192.168.20.2 -l 100 & netperf -H 192.168.20.2 -l 100 &

    Source: Debian LTS Advisories, suse_csaf, Debian Security Advisories, BSI WID Portal, BSI CSAF, cvelistv5, NVD (NIST), Microsoft Security Update Guide, CVE.org (MITRE), ENISA EUVD

    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
    LinuxLinux
    • —
    • 6.2 – < 6.6.94
    • 5.16 – < 6.1.142
    • 5.11 – < 5.15.186
    • 4.16 – < 5.4.295
    • 5.5 – < 5.10.239
    • 6.13 – < 6.15.3
    • 6.7 – < 6.12.34
    • 6.16
    • 6.6.94
    • 6.1.142
    • 5.15.186
    • 5.4.295
    • 5.10.239
    • 6.15.3
    • 6.12.34

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebiandebian_linux11.0
    Linuxdebianlinuxbookworm
    Linuxdebianlinuxbullseye
    Linuxdebianlinux-6.1bullseye
    Linuxlinuxlinux_kernel6.16
    Linuxlinuxlinux_kernel—

    References & sources

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Record modifiedLinux

      Show 24 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://git.kernel.org/stable/c/5814a7fc3abb41f63f2d44c9d3ff9d4e62965b72
      Referenceadded
      —
      https://git.kernel.org/stable/c/82448d4dcd8406dec688632a405fdcf7f170ec69
      Referenceadded
      —
      https://git.kernel.org/stable/c/82ffbe7776d0ac084031f114167712269bf3d832
      Referenceadded
      —
      https://git.kernel.org/stable/c/9c19498bdd7cb9d854bd3c54260f71cf7408495e
      Referenceadded
      —
      https://git.kernel.org/stable/c/b44f791f27b14c9eb6b907fbe51f2ba8bec32085
      Referenceadded
      —
      https://git.kernel.org/stable/c/b4e9bab6011b9559b7c157b16b91ae46d4d8c533
      Referenceadded
      —
      https://git.kernel.org/stable/c/c337efb20d6d9f9bbb4746f6b119917af5c886dc
      Referenceadded
      —
      https://git.kernel.org/stable/c/d1bc80da75c789f2f6830df89d91fb2f7a509943
      Referenceremoved
      https://git.kernel.org/stable/c/5814a7fc3abb41f63f2d44c9d3ff9d4e62965b72
      —
      Referenceremoved
      https://git.kernel.org/stable/c/82448d4dcd8406dec688632a405fdcf7f170ec69
      —
      Referenceremoved
      https://git.kernel.org/stable/c/82ffbe7776d0ac084031f114167712269bf3d832
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      Referenceremoved
      https://git.kernel.org/stable/c/9c19498bdd7cb9d854bd3c54260f71cf7408495e
      —
      Referenceremoved
      https://git.kernel.org/stable/c/b44f791f27b14c9eb6b907fbe51f2ba8bec32085
      —
      Referenceremoved
      https://git.kernel.org/stable/c/b4e9bab6011b9559b7c157b16b91ae46d4d8c533
      —
      Referenceremoved
      https://git.kernel.org/stable/c/c337efb20d6d9f9bbb4746f6b119917af5c886dc
      —
      Referenceremoved
      https://git.kernel.org/stable/c/d1bc80da75c789f2f6830df89d91fb2f7a509943
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/5814a7fc3abb41f63f2d44c9d3ff9d4e62965b72 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/82448d4dcd8406dec688632a405fdcf7f170ec69 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/82ffbe7776d0ac084031f114167712269bf3d832 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/9c19498bdd7cb9d854bd3c54260f71cf7408495e Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/b44f791f27b14c9eb6b907fbe51f2ba8bec32085 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/b4e9bab6011b9559b7c157b16b91ae46d4d8c533 Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/c337efb20d6d9f9bbb4746f6b119917af5c886dc Types: Patch
      —
      Reference typeremoved
      https://git.kernel.org/stable/c/d1bc80da75c789f2f6830df89d91fb2f7a509943 Types: Patch
      —

      Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    2. Record modifiedCISA ADP

      CISA assessment (SSVC): exploitation: none known, automatable: no

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      SSVC assessmentadded
      —
      {"id":"CVE-2025-38115","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"total"}],"version":"2.0.3","timestamp":"2026-10-15T21:47:38.082535Z"}

      Source identifier: 134c704f-9b21-4f2e-91b3-4a467353bcc0

    3. Record modifiedCVE Program

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Referenceadded
      —
      https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
      Referenceadded
      —
      https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
      Referenceremoved
      https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
      —
      Referenceremoved
      https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
      —
      Reference typeremoved
      https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Types: Third Party Advisory
      —
      Reference typeremoved
      https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Types: Third Party Advisory
      —

      Source identifier: af854a3a-2127-422b-91ae-364da2661108

    4. Record modifiedLinux

      CVSS V3.1: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      CVSSadded
      —
      AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

      Source identifier: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

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