CVE-2026-43139Network attack vector

Invalid route-state lookup via uninitialized address

Published May 6, 2026 · Updated May 6, 2026

Use of uninitialized data in affected Linux Kernel releases allows remote attackers to trigger invalid IPv6 route-state lookups. xfrm6_get_saddr() ignores an EADDRNOTAVAIL result from ipv6_dev_get_saddr(), returns success, and leaves saddr->in6 uninitialized for xfrm_state_find(). The failure requires IPv6 source-address selection to find no suitable address; the record demonstrates a KMSAN warning but documents neither a crash nor direct data exposure.

CVSS severity8.6
High
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use of uninitialized data in affected Linux Kernel releases allows remote attackers to trigger invalid IPv6 route-state lookups. xfrm6_get_saddr() ignores an EADDRNOTAVAIL result from ipv6_dev_get_saddr(), returns success, and leaves saddr->in6 uninitialized for xfrm_state_find(). The failure requires IPv6 source-address selection to find no suitable address; the record demonstrates a KMSAN warning but documents neither a crash nor direct data exposure.

The record

CVE
CVE-2026-43139
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-908
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 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=2.6.19
  2. Affected versionversion=a1e59abf824969554b90facd44a4ab16e265afa4 <1799d8abeabc68ec05679292aaf6cba93b343c05
  3. Affected versionversion=a1e59abf824969554b90facd44a4ab16e265afa4 <3dcd1664ac15eee6a690daec7c4ffc59190406f7
  4. Affected versionversion=a1e59abf824969554b90facd44a4ab16e265afa4 <4f28141786e1fe884ce42a5197ba9beed540f0ea
  5. Affected versionversion=a1e59abf824969554b90facd44a4ab16e265afa4 <6535867673bf301d52aa00593a4d1d18cc3922fa
  6. Affected versionversion=a1e59abf824969554b90facd44a4ab16e265afa4 <719918fc88df6da023dfff370cd965151a5afd7f
  7. Affected versionversion=a1e59abf824969554b90facd44a4ab16e265afa4 <c7221e7bd8fc2ef38a0b27be580d9d202281306b
  8. Affected versionversion=a1e59abf824969554b90facd44a4ab16e265afa4 <dc0abce055134cb83b0d981d31ceb20dda419787
  9. Affected versionversion=a1e59abf824969554b90facd44a4ab16e265afa4 <eb2ee15290af14c60b45cf2b73f5687d1d077d9b

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=2.6.19; version=a1e59abf824969554b90facd44a4ab16e265afa4 <1799d8abeabc68ec05679292aaf6cba93b343c05; version=a1e59abf824969554b90facd44a4ab16e265afa4 <3dcd1664ac15eee6a690daec7c4ffc59190406f7; version=a1e59abf824969554b90facd44a4ab16e265afa4 <4f28141786e1fe884ce42a5197ba9beed540f0ea; version=a1e59abf824969554b90facd44a4ab16e265afa4 <6535867673bf301d52aa00593a4d1d18cc3922fa; version=a1e59abf824969554b90facd44a4ab16e265afa4 <719918fc88df6da023dfff370cd965151a5afd7f; version=a1e59abf824969554b90facd44a4ab16e265afa4 <c7221e7bd8fc2ef38a0b27be580d9d202281306b; version=a1e59abf824969554b90facd44a4ab16e265afa4 <dc0abce055134cb83b0d981d31ceb20dda419787; version=a1e59abf824969554b90facd44a4ab16e265afa4 <eb2ee15290af14c60b45cf2b73f5687d1d077d9b

Published CVSS scores

8.6kernel.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/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

CWE-908Use of Uninitialized Resource

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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