CVE-2026-31682Network attack vector

Kernel memory disclosure via nonlinear ND option parsing

Published Apr 25, 2026 · Updated Apr 25, 2026

Out-of-bounds read in Linux Kernel bridge ND handling allows remote attackers to read kernel memory via crafted IPv6 traffic. The br_nd_send() function parses ns->opt[] even when Neighbor Discovery options remain in nonlinear socket-buffer fragments, so parsing runs past the linear buffer. Reachability requires IPv6 Neighbor Solicitation traffic to the bridge path with fragmented option storage; the bounded impacts are kernel-memory disclosure and service interruption.

CVSS severity9.1
Critical
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux Kernel bridge ND handling allows remote attackers to read kernel memory via crafted IPv6 traffic. The br_nd_send() function parses ns->opt[] even when Neighbor Discovery options remain in nonlinear socket-buffer fragments, so parsing runs past the linear buffer. Reachability requires IPv6 Neighbor Solicitation traffic to the bridge path with fragmented option storage; the bounded impacts are kernel-memory disclosure and service interruption.

The record

CVE
CVE-2026-31682
Published
Apr 25, 2026
Updated
Apr 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.15
  2. Affected versionversion=ed842faeb2bd49256f00485402f3113205f91d30 <2ba4caba423ed94d63006eb1d2227b0332ab7fcd
  3. Affected versionversion=ed842faeb2bd49256f00485402f3113205f91d30 <3a30f6469b058574f49efde61cd6f5d79e576053
  4. Affected versionversion=ed842faeb2bd49256f00485402f3113205f91d30 <4f397b950c916e9a1f8a4fce04ea0110206cad47
  5. Affected versionversion=ed842faeb2bd49256f00485402f3113205f91d30 <658261898130da620fc3d0fbb0523efb3366cb55
  6. Affected versionversion=ed842faeb2bd49256f00485402f3113205f91d30 <9c55e41c73af5c4511070933b1bd25248521270c
  7. Affected versionversion=ed842faeb2bd49256f00485402f3113205f91d30 <a01aee7cafc575bb82f5529e8734e7052f9b16ea
  8. Affected versionversion=ed842faeb2bd49256f00485402f3113205f91d30 <bd91ec85aa4c77d645bd2739fc56784157a88ca2
  9. Affected versionversion=ed842faeb2bd49256f00485402f3113205f91d30 <c68433fd291c9e88c00292095172c62d1997d662

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.15; version=ed842faeb2bd49256f00485402f3113205f91d30 <2ba4caba423ed94d63006eb1d2227b0332ab7fcd; version=ed842faeb2bd49256f00485402f3113205f91d30 <3a30f6469b058574f49efde61cd6f5d79e576053; version=ed842faeb2bd49256f00485402f3113205f91d30 <4f397b950c916e9a1f8a4fce04ea0110206cad47; version=ed842faeb2bd49256f00485402f3113205f91d30 <658261898130da620fc3d0fbb0523efb3366cb55; version=ed842faeb2bd49256f00485402f3113205f91d30 <9c55e41c73af5c4511070933b1bd25248521270c; version=ed842faeb2bd49256f00485402f3113205f91d30 <a01aee7cafc575bb82f5529e8734e7052f9b16ea; version=ed842faeb2bd49256f00485402f3113205f91d30 <bd91ec85aa4c77d645bd2739fc56784157a88ca2; version=ed842faeb2bd49256f00485402f3113205f91d30 <c68433fd291c9e88c00292095172c62d1997d662

Published CVSS scores

5.4Amazon LinuxCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
9.1Linux CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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