CVE-2026-64551Network attack vectorHinoki check available

Memory disclosure via unchecked SCTP cause length

Published Jul 27, 2026 · Updated Jul 27, 2026

Out-of-bounds read in the SCTP subsystem of the Linux Kernel allows remote attackers to disclose uninitialized memory via malformed errors. sctp_sf_do_5_2_6_stale() reads four bytes after a cause header without verifying that the dispatched STALE_COOKIE cause contains its staleness field, then echoes the value in a reply INIT. Any peer that drives an association into COOKIE_ECHOED can receive leaked kernel memory; an unprivileged process can also reach the path through a raw SCTP socket in user and network namespaces.

CVSS severity9.1
Critical
EPSS probability0.51%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Out-of-bounds read in the SCTP subsystem of the Linux Kernel allows remote attackers to disclose uninitialized memory via malformed errors. sctp_sf_do_5_2_6_stale() reads four bytes after a cause header without verifying that the dispatched STALE_COOKIE cause contains its staleness field, then echoes the value in a reply INIT. Any peer that drives an association into COOKIE_ECHOED can receive leaked kernel memory; an unprivileged process can also reach the path through a raw SCTP socket in user and network namespaces.

The record

CVE
CVE-2026-64551
Published
Jul 27, 2026
Updated
Jul 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 27, 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 <08a8f2d13f703924316e9aeac863a88ef50990c7
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1cd23ca80784223fa2204e16203f754da4e821f8
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <588706ebaf8cdb4a4161602949eba365514b1db1
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6022da37786701df1fc5dd946a6dcba59d5473b1
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <861f884f5471632c731cbbd612a1c072e391a624
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a257b41ddfe9e327b26581ad2777f04b23ac73f5
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bbd6b2ea966cf57b6ae095cf5a8dbc993cd197a0
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ebe0a55d954fa8da383b6192edb8f763dcb002d5
  9. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <08a8f2d13f703924316e9aeac863a88ef50990c7; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1cd23ca80784223fa2204e16203f754da4e821f8; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <588706ebaf8cdb4a4161602949eba365514b1db1; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6022da37786701df1fc5dd946a6dcba59d5473b1; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <861f884f5471632c731cbbd612a1c072e391a624; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <a257b41ddfe9e327b26581ad2777f04b23ac73f5; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bbd6b2ea966cf57b6ae095cf5a8dbc993cd197a0; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ebe0a55d954fa8da383b6192edb8f763dcb002d5; version=2.6.12

Published CVSS scores

9.1kernel.orgCVSS: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

T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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