CVE-2026-64450Network attack vector

Memory disclosure via unchecked Gap ACK length

Published Jul 25, 2026 · Updated Jul 25, 2026

Out-of-bounds read in Linux Kernel allows remote attackers to disclose kernel memory or crash a TIPC node via a broadcast STATE_MSG. The tipc_bcast_sync_rcv function ignores the Gap ACK record size returned by tipc_get_gap_ack_blks, letting tipc_link_advance_transmq copy beyond a short receive buffer using an attacker-controlled count. Reachability requires a TIPC neighbor that negotiated TIPC_GAP_ACK_BLOCK; a single malformed broadcast STATE_MSG triggers the read.

CVSS severity9.1
Critical
EPSS probability0.54%
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 allows remote attackers to disclose kernel memory or crash a TIPC node via a broadcast STATE_MSG. The tipc_bcast_sync_rcv function ignores the Gap ACK record size returned by tipc_get_gap_ack_blks, letting tipc_link_advance_transmq copy beyond a short receive buffer using an attacker-controlled count. Reachability requires a TIPC neighbor that negotiated TIPC_GAP_ACK_BLOCK; a single malformed broadcast STATE_MSG triggers the read.

The record

CVE
CVE-2026-64450
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 25, 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=5.8
  2. Affected versionversion=d7626b5acff9227e2a65da636a53e09bdafdc0aa <016f5995c37a5a2c45198308f830f244517d70b7
  3. Affected versionversion=d7626b5acff9227e2a65da636a53e09bdafdc0aa <055663d21dc4336f67933ab26bef3c5934be6324
  4. Affected versionversion=d7626b5acff9227e2a65da636a53e09bdafdc0aa <2b66974a1b6134a4bbc3bfed181f7418f688eb54
  5. Affected versionversion=d7626b5acff9227e2a65da636a53e09bdafdc0aa <2de42e268174766cb2e2b90721afdfdff70e0d8d
  6. Affected versionversion=d7626b5acff9227e2a65da636a53e09bdafdc0aa <74b45af86a767594ba52330cd440ea84e24d700d
  7. Affected versionversion=d7626b5acff9227e2a65da636a53e09bdafdc0aa <9a51115fcdc78687c8852bf93a1db3951dbb223b
  8. Affected versionversion=d7626b5acff9227e2a65da636a53e09bdafdc0aa <a21ed5064217cc33726da6c7ef1a520eba43aea1
  9. Affected versionversion=d7626b5acff9227e2a65da636a53e09bdafdc0aa <f333b6851bdf326fd2134133272dbbed0c94d921

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=5.8; version=d7626b5acff9227e2a65da636a53e09bdafdc0aa <016f5995c37a5a2c45198308f830f244517d70b7; version=d7626b5acff9227e2a65da636a53e09bdafdc0aa <055663d21dc4336f67933ab26bef3c5934be6324; version=d7626b5acff9227e2a65da636a53e09bdafdc0aa <2b66974a1b6134a4bbc3bfed181f7418f688eb54; version=d7626b5acff9227e2a65da636a53e09bdafdc0aa <2de42e268174766cb2e2b90721afdfdff70e0d8d; version=d7626b5acff9227e2a65da636a53e09bdafdc0aa <74b45af86a767594ba52330cd440ea84e24d700d; version=d7626b5acff9227e2a65da636a53e09bdafdc0aa <9a51115fcdc78687c8852bf93a1db3951dbb223b; version=d7626b5acff9227e2a65da636a53e09bdafdc0aa <a21ed5064217cc33726da6c7ef1a520eba43aea1; version=d7626b5acff9227e2a65da636a53e09bdafdc0aa <f333b6851bdf326fd2134133272dbbed0c94d921

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
9.1cve.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 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-125Out-of-bounds Read
T1210Exploitation of Remote Services

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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