CVE-2026-31417Network attack vector

Remote kernel crash via X.25 fragment overflow

Published Apr 13, 2026 · Updated Apr 13, 2026

Integer overflow in the Linux kernel X.25 subsystem allows remote attackers to crash the kernel with fragmented X.25 packets. x25_queue_rx_frame adds each packet length to the 16-bit x25_sock.fraglen value without checking USHRT_MAX, while x25_clear_queues leaves fraglen stale after purging fragment_queue. Reachability requires an X.25 link delivering packets through the kernel X.25 receive path; the published impact is limited to system availability.

CVSS severity7.5
High
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in the Linux kernel X.25 subsystem allows remote attackers to crash the kernel with fragmented X.25 packets. x25_queue_rx_frame adds each packet length to the 16-bit x25_sock.fraglen value without checking USHRT_MAX, while x25_clear_queues leaves fraglen stale after purging fragment_queue. Reachability requires an X.25 link delivering packets through the kernel X.25 receive path; the published impact is limited to system availability.

The record

CVE
CVE-2026-31417
Published
Apr 13, 2026
Updated
Apr 13, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-191, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1734bd85c5e0a7a801295b729efb56b009cb8fc3
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4e2d1bcef78d21247fe8fef13bc7ed95885df2b5
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6e568835ea54a3e1d08e310e34f95d434e739477
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8c92969c197b91c134be27dc3afb64ab468853a9
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a1822cb524e89b4cd2cf0b82e484a2335496a6d9
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f953f11ccf4afe6feb635c08145f4240d9a6b544
  7. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1734bd85c5e0a7a801295b729efb56b009cb8fc3; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4e2d1bcef78d21247fe8fef13bc7ed95885df2b5; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6e568835ea54a3e1d08e310e34f95d434e739477; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8c92969c197b91c134be27dc3afb64ab468853a9; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a1822cb524e89b4cd2cf0b82e484a2335496a6d9; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f953f11ccf4afe6feb635c08145f4240d9a6b544; version=2.6.12

Published CVSS scores

7.5Linux kernel CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-191Integer Underflow (Wrap or Wraparound)
T1499.004Endpoint Denial of Service: Application or System Exploitation

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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