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Linux KernelOperating system · Linux

CVE-2026-31405

CRITICAL · 9.8 CVSS v3.1 Published 2026-04-06
Fix available
A fix is available. Upgrade to 5.10.253 / 5.15.203 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In the Linux kernel, the following vulnerability has been resolved: media: dvb-net: fix OOB access in ULE extension header tables The ule_mandatory_ext_handlers[] and ule_optional_ext_handlers[] tables in handle_one_ule_extension() are declared with 255 elements (valid indices 0-254), but the index htype is derived from network-controlled data as (ule_sndu_type & 0x00FF), giving a range of 0-255. When htype equals 255, an out-of-bounds read occurs on the function pointer table, and the OOB value may be called as a function pointer. Add a bounds check on htype against the array size before either table is accessed. Out-of-range values now cause the SNDU to be discarded.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

In the Linux kernel's DVB-NET subsystem, the ULE extension header handler tables (ule_mandatory_ext_handlers[] and ule_optional_ext_handlers[]) are declared with 255 elements (valid indices 0-254), but the index htype is derived from network-controlled data as (ule_sndu_type & 0x00FF), allowing values 0-255. When htype equals 255, an out-of-bounds read occurs and the OOB value may be invoked as a function pointer, enabling remote code execution.

MitigationApply the kernel patch to add bounds checking on htype before table access. Until patched, consider network isolation or disabling DVB networking functionality if not required, as the attack vector is network-adjacent.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:>= 2.6.12.1, < 5.10.253>= 5.11, < 5.15.203>= 5.16, < 6.1.167>= 6.2, < 6.6.130>= 6.7, < 6.12.78>= 6.13, < 6.18.19>= 6.19, < 6.19.9= 2.6.12= 7.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check kernel version
    Run `uname -r` or check `/proc/version` to get the running kernel version
    Affected if The kernel version falls within any of these ranges: >= 2.6.12.1 and < 5.10.253; >= 5.11 and < 5.15.203; >= 5.16 and < 6.1.167; >= 6.2 and < 6.6.130; >= 6.7 and < 6.12.78; >= 6.13 and < 6.18.19; >= 6.19 and < 6.19.9; equals 2.6.12 or 7.0
  2. Verify DVB kernel modules are loaded
    Run `lsmod | grep -i dvb` or check `/sys/class/dvb/` directory existence to see if any DVB modules are present
    Affected if DVB modules such as dvb_core, dvb_net, or related network handlers are loaded or the /sys/class/dvb/ directory exists on the system
  3. Check for DVB network interface configuration
    Run `ip link show` or check `/etc/network/interfaces` and related config for dvb interfaces (typically named dvb0_*)
    Affected if Any DVB network interfaces are configured or present on the system, indicating the DVB network stack is in use
  4. Confirm ULE extension handling is active
    Check kernel config for CONFIG_DVB_NET (run `zcat /proc/config.gz 2>/dev/null | grep CONFIG_DVB_NET` or check /boot/config-$(uname -r))
    Affected if CONFIG_DVB_NET=y or CONFIG_DVB_NET=m is set, enabling the ULE extension handler code path where the vulnerability resides
  5. Identify if system receives untrusted DVB streams
    Review system logs, DVB hardware configuration, or network monitoring for incoming DVB transport stream traffic
    Affected if The system is configured to receive or process DVB broadcast streams from untrusted sources, which would trigger the handle_one_ule_extension function with attacker-controlled htype values

A system is affected if it runs a vulnerable kernel version AND has the DVB network stack (CONFIG_DVB_NET) enabled while processing DVB broadcast streams that could deliver a crafted htype value of 255.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.10.253 / 5.15.203 / 6.1.167 or later
Fixed in 5.10.2535.15.2036.1.167
Vendor patch git.kernel.org →
Interim mitigation

Apply the kernel patch to add bounds checking on htype before table access. Until patched, consider network isolation or disabling DVB networking functionality if not required, as the attack vector is network-adjacent.

Recommended fix High confidence

Upgrade to kernel 5.10.253+, 5.15.203+, 6.1.167+, or 6.6.130+ depending on which major version branch you are on

  1. Identify the currently running Linux kernel version using `uname -r`
  2. Determine which version range your current kernel falls into (5.10.x, 5.11-5.14, 5.16-6.1, or 6.2-6.6)
  3. For 5.10.x kernels: upgrade to kernel version 5.10.253 or later
  4. For 5.11-5.14 kernels: upgrade to kernel version 5.15.203 or later (note: 5.15 is the LTS successor to 5.11-5.14)
  5. For 5.16-6.1 kernels: upgrade to kernel version 6.1.167 or later
  6. For 6.2-6.6 kernels: upgrade to kernel version 6.6.130 or later
  7. Use your distribution's package manager to install the new kernel (e.g., `apt-get update && apt-get install linux-image-<version>` for Debian/Ubuntu, or `yum update kernel` for RHEL/CentOS)
  8. Reboot the system to load the new kernel
Caveat Kernel upgrades may require system reboot and could have compatibility implications with custom modules or specific hardware drivers; test in non-production environment first

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,340
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-31405 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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