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VulnerabilityPublished Updated

CVE-2026-43139: Linux kernel · xfrm6: fix uninitialized saddr in xfrm6_get_saddr()

Source GCVE Database

0
Authoritative record:CVE-2026-43139· High 8.6

Not known to be exploited · CVSS 8.6 High · fixed in eb2ee15290af14c60b45cf2b73f5687d1d077d9b : patch Linux kernel soon.

Data as of 27 Oct 2026, 00:07 UTC

CVSS 3.1 base score
8.6High
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in eb2ee15290af14c60b45cf2b73f5687d1d077d9b, dc0abce055134cb83b0d981d31ceb20dda419787, c7221e7bd8fc2ef38a0b27be580d9d202281306b +5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 6 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < eb2ee15290af14c60b45cf2b73f5687d1d077d9b
Fixed in
  • eb2ee15290af14c60b45cf2b73f5687d1d077d9b
LinuxLinuxAffected
  • ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < dc0abce055134cb83b0d981d31ceb20dda419787
Fixed in
  • dc0abce055134cb83b0d981d31ceb20dda419787
LinuxLinuxAffected
  • ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < c7221e7bd8fc2ef38a0b27be580d9d202281306b
Fixed in
  • c7221e7bd8fc2ef38a0b27be580d9d202281306b
LinuxLinuxAffected
  • ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < 6535867673bf301d52aa00593a4d1d18cc3922fa
Fixed in
  • 6535867673bf301d52aa00593a4d1d18cc3922fa
LinuxLinuxAffected
  • ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < 719918fc88df6da023dfff370cd965151a5afd7f
Fixed in
  • 719918fc88df6da023dfff370cd965151a5afd7f
LinuxLinuxAffected
  • ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < 1799d8abeabc68ec05679292aaf6cba93b343c05
Fixed in
  • 1799d8abeabc68ec05679292aaf6cba93b343c05

Description

In the Linux kernel, the following vulnerability has been resolved: xfrm6: fix uninitialized saddr in xfrm6_get_saddr() xfrm6_get_saddr() does not check the return value of ipv6_dev_get_saddr(). When ipv6_dev_get_saddr() fails to find a suitable source address (returns -EADDRNOTAVAIL), saddr->in6 is left uninitialized, but xfrm6_get_saddr() still returns 0 (success). This causes the caller xfrm_tmpl_resolve_one() to use the uninitialized address in xfrm_state_find(), triggering KMSAN warning: ===================================================== BUG: KMSAN: uninit-value in xfrm_state_find+0x2424/0xa940 xfrm_state_find+0x2424/0xa940 xfrm_resolve_and_create_bundle+0x906/0x5a20 xfrm_lookup_with_ifid+0xcc0/0x3770 xfrm_lookup_route+0x63/0x2b0 ip_route_output_flow+0x1ce/0x270 udp_sendmsg+0x2ce1/0x3400 inet_sendmsg+0x1ef/0x2a0 __sock_sendmsg+0x278/0x3d0 __sys_sendto+0x593/0x720 __x64_sys_sendto+0x130/0x200 x64_sys_call+0x332b/0x3e70 do_syscall_64+0xd3/0xf80 entry_SYSCALL_64_after_hwframe+0x77/0x7f Local variable tmp.i.i created at: xfrm_resolve_and_create_bundle+0x3e3/0x5a20 xfrm_lookup_with_ifid+0xcc0/0x3770 ===================================================== Fix by checking the return value of ipv6_dev_get_saddr() and propagating the error.

References

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