CriticalCVE-2026-89846

    Linux Kernel: Out-of-Bounds Read (CVE-2026-89846)

    Published Last modified Sources: HKCERT, Ubuntu, Debian LTS, Red Hat, Debian, CVE.org, BSI

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    What is affected, what to do

    A flaw was found in the Linux kernel's `scsi: qla2xxx` driver. A remote attacker, by sending a specially crafted Fibre Channel Protocol (FCP) response, could cause an integer underflow.

    Update Linux Kernel to version 5.10.270, Linux Kernel to version 5.15.221, Linux Kernel to version 6.1.188.

    Affected
    • Linux Kernel lt 2.6.36..5.10.270
    • Linux Kernel lt 5.11..5.15.221
    • Linux Kernel lt 5.16..6.1.188
    • Linux Kernel lt 6.2..6.6.157
    • Linux Kernel lt 6.7..6.12.110
    • Linux Kernel lt 6.13..6.18.51
    • Linux Kernel lt 6.19..7.2.5
    Fixed in
    • Linux Kernel 5.10.270
    • Linux Kernel 5.15.221
    • Linux Kernel 6.1.188
    • Linux Kernel 6.6.157
    • Linux Kernel 6.12.110
    • Linux Kernel 6.18.51
    • Linux Kernel 7.2.5
    • Linux Kernel 7.3

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

    Metrics

    9.1

    Priority

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

    Source: Vendor (CNA), CVSS v3

    9.1

    CVSS v3

    Severity Critical on the scale from 0 to 10.

    Source: HKCERT, Ubuntu, Debian LTS, Red Hat, Debian, CVE.org, BSI

    0.7 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 53.7

    Show all metrics
    Severity
    Critical
    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
    95.19 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
    9.1 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
    9.1
    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
    0.7 %
    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
    53.7
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    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

    A flaw was found in the Linux kernel's `scsi: qla2xxx` driver. A remote attacker, by sending a specially crafted Fibre Channel Protocol (FCP) response, could cause an integer underflow. This underflow leads to an out-of-bounds read when handling sense data, potentially disclosing sensitive memory information from the kernel's heap.

    Source: HKCERT (CC BY 3.0 HK) · HKCERT rating: medium, Ubuntu Security Notices, Debian LTS Advisories, redhat_csaf, Debian Security Advisories, 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
    • 2.6.36 – < 5.10.270
    • 6.13 – < 6.18.51
    • 6.19 – < 7.2.5
    • 5.11 – < 5.15.221
    • —
    • 6.7 – < 6.12.110
    • 5.16 – < 6.1.188
    • 6.2 – < 6.6.157
    • 5.10.270
    • 6.18.51
    • 7.2.5
    • 5.15.221
    • 7.3
    • 6.12.110
    • 6.1.188
    • 6.6.157

    Vendors and products

    Affected operating systems

    Affected operating systems
    Linuxdebianlinuxbookworm
    Linuxdebianlinuxtrixie
    Linuxubuntulinuxjammy
    Linuxubuntulinuxresolute
    Linuxdebianlinux-6.12bookworm
    Linuxubuntulinux-awsjammy
    Linuxubuntulinux-awsresolute
    Linuxubuntulinux-aws-5.15focal
    Linuxubuntulinux-aws-fipsjammy
    Linuxubuntulinux-azurejammy
    Linuxubuntulinux-azure-5.15focal
    Linuxubuntulinux-azure-fdejammy
    Linuxubuntulinux-azure-fde-5.15focal
    Linuxubuntulinux-azure-fipsjammy
    Linuxubuntulinux-fipsjammy
    Linuxubuntulinux-gcpjammy
    Linuxubuntulinux-gcpresolute
    Linuxubuntulinux-gcp-5.15focal
    Linuxubuntulinux-gcp-fipsjammy
    Linuxubuntulinux-gkejammy
    Linuxubuntulinux-gkeopjammy
    Linuxubuntulinux-hwe-5.15focal
    Linuxubuntulinux-hwe-7.0noble
    Linuxubuntulinux-ibmjammy

    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

      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/2026/89xxx/CVE-2026-89846.json">CVE-2026-89846</a>

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

    2. Record modifiedLinux

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

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

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

    3. ReceivedLinux

      Description added or changed

      Show 10 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      In the Linux kernel, the following vulnerability has been resolved: scsi: qla2xxx: Bound rsp_info_len to avoid OOB sense-data read In qla2x00_status_entry(), the FWI2 status path advances sense_data and shrinks par_sense_len by rsp_info_len: if (IS_FWI2_CAPABLE(ha)) { sense_data += rsp_info_len; par_sense_len -= rsp_info_len; } rsp_info_len is a 32-bit value taken directly from the target's FCP response (sf.rsp_data_len), while par_sense_len is the IOCB data area size (28 bytes for 24xx, 60 bytes for 29xx). A hostile or buggy target reporting an rsp_info_len larger than par_sense_len makes the unsigned subtraction underflow to a huge value and advances sense_data out of bounds. The underflowed par_sense_len then defeats the cap in qla2x00_handle_sense(): if (sense_len > par_sense_len) sense_len = par_sense_len; memcpy(cp->sense_buffer, sense_data, sense_len); so the memcpy reads up to SCSI_SENSE_BUFFERSIZE bytes from the out-of-bounds sense_data pointer, leaking adjacent response-ring/heap memory into the command's sense buffer. Clamp rsp_info_len to par_sense_len before the subtraction so par_sense_len can never underflow and sense_data stays within the IOCB data area. The fix sits before the comp_status switch, covering both qla2x00_handle_sense() call sites.
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/89xxx/CVE-2026-89846.json">CVE-2026-89846</a>
      Referenceadded
      —
      https://git.kernel.org/stable/c/125b12861c726e58448bb95d55b04851fb131d1f
      Referenceadded
      —
      https://git.kernel.org/stable/c/6b08c0cb110a1fba92f99d655020198489699815
      Referenceadded
      —
      https://git.kernel.org/stable/c/be75ab791c9b3baca66c70ce03443afebc83acda
      Referenceadded
      —
      https://git.kernel.org/stable/c/ca6d880d6c70cb7946e7b3e05d7285f271b6d99e
      Referenceadded
      —
      https://git.kernel.org/stable/c/d7f7746ff031ae45724881261804f4bf5317c985
      Referenceadded
      —
      https://git.kernel.org/stable/c/e57ace988bda5693f7b3645f652ea4b4220870ee
      Referenceadded
      —
      https://git.kernel.org/stable/c/ebc41dfc59d190956e0113e8bd90c28f6f21e8b9
      Referenceadded
      —
      https://git.kernel.org/stable/c/f6e8977bce887481b2b2b0e2e14a791270741cfb

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

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