HighCVE-2026-98857

    Linux Kernel: security vulnerability (CVE-2026-98857)

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

    What is affected, what to do

    In the Linux kernel, the following vulnerability has been resolved: ipvs: bound LBLCR and LBLC cache growth ip_vs_lblcr_new() and ip_vs_lblc_new() create cache entries for every previously unseen destination address. The table max_size only tells the periodic collector to reclaim entries after the cache has already exceeded the limit.

    Update Linux Kernel to version 5.10.273, Linux Kernel to version 5.15.224, Linux Kernel to version 6.1.191.

    Affected
    • Linux Kernel lt 2.6.12..5.10.273
    • Linux Kernel lt 5.11..5.15.224
    • Linux Kernel lt 5.16..6.1.191
    • Linux Kernel lt 6.2..6.6.160
    • Linux Kernel lt 6.7..6.12.113
    • Linux Kernel lt 6.13..6.18.56
    • Linux Kernel lt 6.19..7.2.10
    Fixed in
    • Linux Kernel 5.10.273
    • Linux Kernel 5.15.224
    • Linux Kernel 6.1.191
    • Linux Kernel 6.6.160
    • Linux Kernel 6.12.113
    • Linux Kernel 6.18.56
    • Linux Kernel 7.2.10
    • Linux Kernel 7.3

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    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: Debian LTS, Msrc Update Guide, CVE.org, BSI

    0.2 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 5.6

    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
    67.75 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
    7.5 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
    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
    5.6
    Low — this CVE sits in the lower 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: ipvs: bound LBLCR and LBLC cache growth ip_vs_lblcr_new() and ip_vs_lblc_new() create cache entries for every previously unseen destination address. The table max_size only tells the periodic collector to reclaim entries after the cache has already exceeded the limit. It does not reclaim entries that the attacker continues to use. Reject new cache entries once either table reaches max_size * 3 / 2. The extra headroom lets the periodic collector catch up while the existing scheduler fallback continues to use the selected destination when cache creation fails. New traffic therefore stays serviceable without growing the tables further.

    Source: Debian LTS Advisories, Microsoft Security Update Guide, cvelistv5, NVD (NIST), BSI WID Portal, BSI CSAF

    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
    • 5.11 – < 5.15.224
    • 5.16 – < 6.1.191
    • 6.13 – < 6.18.56
    • 6.19 – < 7.2.10
    • 6.7 – < 6.12.113
    • —
    • 2.6.12 – < 5.10.273
    • 6.2 – < 6.6.160
    • 5.15.224
    • 6.1.191
    • 6.18.56
    • 7.2.10
    • 6.12.113
    • 7.3
    • 5.10.273
    • 6.6.160

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinux-6.12bookworm

    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 4 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98857.json">CVE-2026-98857</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/488eaba207dd2e4c5afc65e18dc237d70f01d283
      Referenceadded
      —
      https://git.kernel.org/stable/c/8b93288b4543ad5139a25a5b211a07bf755652dd
      Referenceadded
      —
      https://git.kernel.org/stable/c/f6e9446bfb79907d3092fc45a0054b0c3b329bfe

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

    2. Record modifiedLinux

      Show 2 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98857.json">CVE-2026-98857</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/bc9ff8e64771cc32a216953fe615386f46ac1eaa

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

    3. Record modifiedLinux

      1 individual change: Affected versions (publisher)

      Show the original change
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Affected versions (publisher)added
      —
      Affected value modified. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98857.json">CVE-2026-98857</a>

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

    4. ReceivedLinux

      Description added or changed

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      In the Linux kernel, the following vulnerability has been resolved: ipvs: bound LBLCR and LBLC cache growth ip_vs_lblcr_new() and ip_vs_lblc_new() create cache entries for every previously unseen destination address. The table max_size only tells the periodic collector to reclaim entries after the cache has already exceeded the limit. It does not reclaim entries that the attacker continues to use. Reject new cache entries once either table reaches max_size * 3 / 2. The extra headroom lets the periodic collector catch up while the existing scheduler fallback continues to use the selected destination when cache creation fails. New traffic therefore stays serviceable without growing the tables further.
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/98xxx/CVE-2026-98857.json">CVE-2026-98857</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/16c83c047ecfaf226ad81d45d77fa11a3184d0e4
      Referenceadded
      —
      https://git.kernel.org/stable/c/2a3c3de660f96865f303fd25f1285f2ffbfd521d
      Referenceadded
      —
      https://git.kernel.org/stable/c/31028d7b970962fbeda1e9131405c76551094300
      Referenceadded
      —
      https://git.kernel.org/stable/c/6316d17324bd4ca400c26adb7b656c6e3447c209

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

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