7.1

CVE-2026-64576: linux Use of Uninitialized Variable

CVSS: 7.1v3.1HighReceived
AliasesUBUNTU-CVE-2026-64576DEBIAN-CVE-2026-64576
Published 05-08-2026Last modified 19-10-2026
Open JSON

Vulnerability summary

CVE-2026-64576 is a high (CVSS 7.1) Use of Uninitialized Variable vulnerability in linux. EPSS estimates a 0.12% chance of exploitation in the next 30 days, higher than 1.5% of scored vulnerabilities.

Overall risk
28/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.1/10
010
High · v3.1 (CVE.org)
EPSS score
0.12%
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 29 · Related 25
MGASA-2026-0336MGASA-2026-0337OPENSUSE-SU-2026:11476-1OPENSUSE-SU-2026:21910-1SUSE-SU-2026:23477-1SUSE-SU-2026:23481-1

Timeline

  1. 05-08-2026
    PublishedVulnerability first disclosed.
  2. 19-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: nexthop: initialize extack in nh_res_bucket_migrate() nh_res_bucket_migrate() passes an uninitialized netlink_ext_ack to call_nexthop_res_bucket_notifiers(). When nh_notifier_res_bucket_info_init() fails (e.g. the kzalloc returns -ENOMEM), the error is propagated back before any notifier sets extack._msg, and the error path formats the stale pointer with pr_err_ratelimited("%s\n", extack._msg). With CONFIG_INIT_STACK_NONE this dereferences uninitialized stack memory: Oops: general protection fault, probably for non-canonical address ... KASAN: maybe wild-memory-access in range [...] RIP: 0010:string (lib/vsprintf.c:730) vsnprintf (lib/vsprintf.c:2945) _printk (kernel/printk/printk.c:2504) nh_res_bucket_migrate (net/ipv4/nexthop.c:1816) nh_res_table_upkeep (net/ipv4/nexthop.c:1866) rtm_new_nexthop (net/ipv4/nexthop.c:3323) rtnetlink_rcv_msg (net/core/rtnetlink.c:7076) netlink_sendmsg (net/netlink/af_netlink.c:1900) Kernel panic - not syncing: Fatal exception Zero-initialize extack so _msg is NULL on error paths that never set it.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.12%

Chance of exploitation in the next 30 days

Percentile

2%

Versus all other CVEs

30-day change

0.00 pp

From 0.12% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.12%

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) | < 5.15.0-198.208 | < 6.8.0-147.147 | < 7.0.0-38.38
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1067.70 | < 7.0.0-1014.14
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian2 products
  • linux< 6.1.187-1 | < 6.12.101-1 | < 7.1.6-1
  • linux-6.12< 6.12.101-1~deb12u1
Linux1 product
  • linux≥ 7c37c7e00411b3d1e0c5292368317aca69d1f324, < eacd2e2117e8682f937967fda1022e7f1c22d91a | ≥ 7c37c7e00411b3d1e0c5292368317aca69d1f324, < 37bbd7e1d8df0bec3d187e961783e20c30533d2c | ≥ 7c37c7e00411b3d1e0c5292368317aca69d1f324, < c0936c131a71657afc635d0db2ab096d15d473e1 | ≥ 7c37c7e00411b3d1e0c5292368317aca69d1f324, < 3081702ea5aca0aeed9c1ade8eadf6cde8db6b7d | ≥ 7c37c7e00411b3d1e0c5292368317aca69d1f324, < d536bf205c71f700f6de2086038c3e1d77724715 | ≥ 7c37c7e00411b3d1e0c5292368317aca69d1f324, < 18506d7263768d76ac8e057ba55a4d9da50aad66 | ≥ 7c37c7e00411b3d1e0c5292368317aca69d1f324, < 6347c5314cee49f364aaf2e40ff15415a57a116e | 5.13

3 vendors · 160 products

References

27 links
Show all 27 references