CVE-2024-26857Network attack vector

Tunnel packet drops via unpulled inner header

Published Apr 17, 2024 · Updated Aug 5, 2026

Uninitialized-value use in the GENEVE receive path in Linux allows remote attackers to disrupt tunneled traffic with crafted UDP packets. geneve_rx retains skb->network_header across pskb_inet_may_pull without recomputing it, so ECN decapsulation reads one or two stale heap bytes past valid packet data. A reachable GENEVE UDP endpoint is required; the resulting oracle can mark or discard packets but does not directly disclose the bytes or crash production kernels.

CVSS severity7.3
High
EPSS probability0.60%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uninitialized-value use in the GENEVE receive path in Linux allows remote attackers to disrupt tunneled traffic with crafted UDP packets. geneve_rx retains skb->network_header across pskb_inet_may_pull without recomputing it, so ECN decapsulation reads one or two stale heap bytes past valid packet data. A reachable GENEVE UDP endpoint is required; the resulting oracle can mark or discard packets but does not directly disclose the bytes or crash production kernels.

The record

CVE
CVE-2024-26857
Published
Apr 17, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1498
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 17, 2024CVE 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=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <048e16dee1fc609c1c85072ccd70bfd4b5fef6ca
  2. Affected versionversion=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <0ece581d2a66e8e488c0d3b3e7b5760dbbfdbdd5
  3. Affected versionversion=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <1ca1ba465e55b9460e4e75dec9fff31e708fec74
  4. Affected versionversion=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <59d2a4076983303f324557a114cfd5c32e1f6b29
  5. Affected versionversion=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <c0b22568a9d8384fd000cc49acb8f74bde40d1b5
  6. Affected versionversion=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <c7137900691f5692fe3de54566ea7b30bb35d66c
  7. Affected versionversion=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <e431c3227864b5646601c97f5f898d99472f2914
  8. Affected versionversion=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <e77e0b0f2a11735c64b105edaee54d6344faca8a
  9. Affected versionversion=4.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <048e16dee1fc609c1c85072ccd70bfd4b5fef6ca; version=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <0ece581d2a66e8e488c0d3b3e7b5760dbbfdbdd5; version=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <1ca1ba465e55b9460e4e75dec9fff31e708fec74; version=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <59d2a4076983303f324557a114cfd5c32e1f6b29; version=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <c0b22568a9d8384fd000cc49acb8f74bde40d1b5; version=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <c7137900691f5692fe3de54566ea7b30bb35d66c; version=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <e431c3227864b5646601c97f5f898d99472f2914; version=2d07dc79fe04a43d82a346ced6bbf07bdb523f1b <e77e0b0f2a11735c64b105edaee54d6344faca8a; version=4.2

Published CVSS scores

7.3Linux Kernel CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

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

T1498Network Denial of Service

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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