CVE-2026-53275 | ipv6: mcast: Fix use-after-free when processing MLD queries

In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: Fix use-after-free when processing MLD queries When processing an MLD query, a pointer to the multicast group address is retrieved when initially parsing the packet. This pointer is later dereferenced without being reloaded despite the fact that the skb header might have been reallocated following the pskb_may_pull() calls, leading to a use-after-free [1]. Fix by copying the multicast group address when the packet is initially parsed. [1] BUG: KASAN: slab-use-after-free in __mld_query_work (net/ipv6/mcast.c:1512) Read of size 8 at addr ffff8881154b8e90 by task kworker/4:1/118 Workqueue: mld mld_query_work Call Trace: <TASK> dump_stack_lvl (lib/dump_stack.c:94 lib/dump_stack.c:120) print_address_description.constprop.0 (mm/kasan/report.c:378) print_report (mm/kasan/report.c:482) kasan_report (mm/kasan/report.c:595) __mld_query_work (net/ipv6/mcast.c:1512) mld_query_work (net/ipv6/mcast.c:1563) process_one_work (kernel/workqueue.c:3314) worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245) </TASK> [...] Freed by task 118: kasan_save_stack (mm/kasan/common.c:57) kasan_save_track (mm/kasan/common.c:78) kasan_save_free_info (mm/kasan/generic.c:584) __kasan_slab_free (mm/kasan/common.c:253 mm/kasan/common.c:285) kfree (./include/linux/kasan.h:235 mm/slub.c:2689 mm/slub.c:6251 mm/slub.c:6566) pskb_expand_head (net/core/skbuff.c:2335) __pskb_pull_tail (net/core/skbuff.c:2878 (discriminator 4)) __mld_query_work (net/ipv6/mcast.c:1495 (discriminator 1)) mld_query_work (net/ipv6/mcast.c:1563) process_one_work (kernel/workqueue.c:3314) worker_thread (kernel/workqueue.c:3397 kernel/workqueue.c:3478) kthread (kernel/kthread.c:436) ret_from_fork (arch/x86/kernel/process.c:158) ret_from_fork_asm (arch/x86/entry/entry_64.S:245)

Published: 2026-06-25 Last update: 2026-06-30 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Awaiting Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-53275 is rated Moderate Risk (41/100): CVSS High severity, with low exploitation likelihood (EPSS 0.25%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-53275

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-28 0.17% 0.25% +0.08%
2 2026-06-25 — 0.17% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-53275

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Weakness enumeration for CVE-2026-53275

GitHub Security Advisory for CVE-2026-53275

GHSA-2pv9-hj5w-6p36 · Severity: high — In the Linux kernel, the following vulnerability has been resolved: ipv6: mcast: Fix use-after...

OS Trackers for CVE-2026-53275

vendor priority summary link
debian not yet assigned CVE-2026-53275 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2026-53275
redhat medium — https://access.redhat.com/security/cve/CVE-2026-53275
suse medium — https://www.suse.com/security/cve/CVE-2026-53275/
ubuntu high CVE-2026-53275 high priority: Ubuntu including 161 source packages (linux, linux-allwinner-5.19, …), 1449 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1044, ignored 172, needed 145, released 87, needs-triage 1. https://ubuntu.com/security/CVE-2026-53275

Affected software / configurations for CVE-2026-53275

Vendor Product Version Raw CPE
linux linux_kernel >= 2.6.15, < 5.15.210 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.15, < 6.1.176 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.15, < 6.6.143 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.15, < 6.12.94 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.15, < 6.18.36 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.15, < 7.0.13 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 2.6.15, < 7.1 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

References for CVE-2026-53275

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