8.6

CVE-2026-43139: linux Use of Uninitialized Resource

CVSS: 8.6v3.1HighModified
AliasesUBUNTU-CVE-2026-43139DEBIAN-CVE-2026-43139
Published 06-05-2026Last modified 19-10-2026
Open JSON

Vulnerability summary

CVE-2026-43139 is a high (CVSS 8.6) Use of Uninitialized Resource vulnerability in linux. EPSS estimates a 0.38% chance of exploitation in the next 30 days, higher than 29.9% of scored vulnerabilities.

Overall risk
34/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.6/10
010
High · v3.1 (CVE.org)
EPSS score
0.38%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 37 · Related 37
OPENSUSE-SU-2026:21388-1SUSE-SU-2026:22521-1SUSE-SU-2026:22522-1SUSE-SU-2026:22665-1SUSE-SU-2026:22666-1SUSE-SU-2026:22742-1

Timeline

  1. 06-05-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.38%

Chance of exploitation in the next 30 days

Percentile

30%

Versus all other CVEs

30-day change

0.00 pp

From 0.38% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.38%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ubuntu157 products
  • linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-134.134
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1060.63
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ a1e59abf824969554b90facd44a4ab16e265afa4, < 4f28141786e1fe884ce42a5197ba9beed540f0ea | ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < 6535867673bf301d52aa00593a4d1d18cc3922fa | ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < eb2ee15290af14c60b45cf2b73f5687d1d077d9b | ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < 719918fc88df6da023dfff370cd965151a5afd7f | ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < dc0abce055134cb83b0d981d31ceb20dda419787 | ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < c7221e7bd8fc2ef38a0b27be580d9d202281306b | ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < 3dcd1664ac15eee6a690daec7c4ffc59190406f7 | ≥ a1e59abf824969554b90facd44a4ab16e265afa4, < 1799d8abeabc68ec05679292aaf6cba93b343c05 | 2.6.19
  • linux_kernel≥ 2.6.19, < 5.10.252 | ≥ 5.11, < 5.15.202 | ≥ 5.16, < 6.1.165 | ≥ 6.2, < 6.6.128 | ≥ 6.7, < 6.12.75 | ≥ 6.13, < 6.18.16 | ≥ 6.19, < 6.19.6 | 7.0:rc1
Debian1 product
  • linux< 6.1.170-1 | < 6.12.85-1 | < 6.19.6-1

3 vendors · 160 products

References

37 links
Show all 37 references