CVE-2026-64577Network attack vector

Remote kernel panic via unchecked packet pull

Published Aug 5, 2026 · Updated Aug 5, 2026

Buffer underwrite in Linux kernel allows remote attackers to panic GTP-enabled systems via a 16–19-byte GTP-U Echo Request. gtp1u_send_echo_resp() ignores a failed 20-byte skb_pull_data() on the short packet, after which skb_push() and iptunnel_xmit() underflow packet-buffer headroom and trigger skb_under_panic(). Reachability requires an in-kernel GTP-U socket created for a GTP device; one unauthenticated UDP datagram can crash the host without disclosing or changing data.

CVSS severity7.5
High
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer underwrite in Linux kernel allows remote attackers to panic GTP-enabled systems via a 16–19-byte GTP-U Echo Request. gtp1u_send_echo_resp() ignores a failed 20-byte skb_pull_data() on the short packet, after which skb_push() and iptunnel_xmit() underflow packet-buffer headroom and trigger skb_under_panic(). Reachability requires an in-kernel GTP-U socket created for a GTP device; one unauthenticated UDP datagram can crash the host without disclosing or changing data.

The record

CVE
CVE-2026-64577
Published
Aug 5, 2026
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-124, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=5.18
  2. Affected versionversion=9af41cc33471ea1efa6f77e188f055cc77d0a5c5 <4fc7923871d176ce0e5fecf4a9b7bb915af790ed
  3. Affected versionversion=9af41cc33471ea1efa6f77e188f055cc77d0a5c5 <961e9b1e33445f8e42859ecc020c9f60d8b69a8b
  4. Affected versionversion=9af41cc33471ea1efa6f77e188f055cc77d0a5c5 <b3c733eaae7f362601c28ac1533d47a961cd3e1c
  5. Affected versionversion=9af41cc33471ea1efa6f77e188f055cc77d0a5c5 <cd170f051dba9ac146fabcd1b91726487c0cb9fa
  6. Affected versionversion=9af41cc33471ea1efa6f77e188f055cc77d0a5c5 <cf45d748e437b8dd2dd987f27ee79c8c86f95c88

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.18; version=9af41cc33471ea1efa6f77e188f055cc77d0a5c5 <4fc7923871d176ce0e5fecf4a9b7bb915af790ed; version=9af41cc33471ea1efa6f77e188f055cc77d0a5c5 <961e9b1e33445f8e42859ecc020c9f60d8b69a8b; version=9af41cc33471ea1efa6f77e188f055cc77d0a5c5 <b3c733eaae7f362601c28ac1533d47a961cd3e1c; version=9af41cc33471ea1efa6f77e188f055cc77d0a5c5 <cd170f051dba9ac146fabcd1b91726487c0cb9fa; version=9af41cc33471ea1efa6f77e188f055cc77d0a5c5 <cf45d748e437b8dd2dd987f27ee79c8c86f95c88

Published CVSS scores

7.5Linux CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.0Red HatCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/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-124Buffer Underwrite ('Buffer Underflow')
T1499.004Application or System Exploitation

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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