CVE-2025-39984
In the Linux kernel, the following vulnerability has been resolved: net: tun: Update napi->skb after XDP process The syzbot report a UAF issue: BUG: KASAN: slab-use-after-free in skb_reset_mac…
Overview
CVE-2025-39984 is a known-severity vulnerability. It was published on October 15, 2025.
Technical description
In the Linux kernel, the following vulnerability has been resolved:
net: tun: Update napi->skb after XDP process
The syzbot report a UAF issue:
BUG: KASAN: slab-use-after-free in skb_reset_mac_header include/linux/skbuff.h:3150 [inline]
BUG: KASAN: slab-use-after-free in napi_frags_skb net/core/gro.c:723 [inline]
BUG: KASAN: slab-use-after-free in napi_gro_frags+0x6e/0x1030 net/core/gro.c:758
Read of size 8 at addr ffff88802ef22c18 by task syz.0.17/6079
CPU: 0 UID: 0 PID: 6079 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x240 mm/kasan/report.c:482
kasan_report+0x118/0x150 mm/kasan/report.c:595
skb_reset_mac_header include/linux/skbuff.h:3150 [inline]
napi_frags_skb net/core/gro.c:723 [inline]
napi_gro_frags+0x6e/0x1030 net/core/gro.c:758
tun_get_user+0x28cb/0x3e20 drivers/net/tun.c:1920
tun_c
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
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Frequently asked questions
What is CVE-2025-39984?
CVE-2025-39984 is a known-severity vulnerability. It was published on October 15, 2025.
How severe is CVE-2025-39984?
CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.
How do I fix or remediate CVE-2025-39984?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-39984?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2025-39984 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.