CVE-2025-21891Use of Uninitialized Resource in Linux

Severity
5.5MEDIUMNVD
OSV4.7
EPSS
0.1%
top 74.36%
CISA KEV
Not in KEV
Exploit
No known exploits
Timeline
PublishedMar 27
Latest updateOct 15

Description

In the Linux kernel, the following vulnerability has been resolved: ipvlan: ensure network headers are in skb linear part syzbot found that ipvlan_process_v6_outbound() was assuming the IPv6 network header isis present in skb->head [1] Add the needed pskb_network_may_pull() calls for both IPv4 and IPv6 handlers. [1] BUG: KMSAN: uninit-value in __ipv6_addr_type+0xa2/0x490 net/ipv6/addrconf_core.c:47 __ipv6_addr_type+0xa2/0x490 net/ipv6/addrconf_core.c:47 ipv6_addr_type include/net/ipv6.h:555

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitability: 1.8 | Impact: 3.6

Affected Packages9 packages

NVDlinux/linux_kernel3.196.1.130+4
Debianlinux/linux_kernel< 6.1.133-1+2
Ubuntulinux/linux_kernel< 6.8.0-84.84
CVEListV5linux/linux2ad7bf3638411cb547f2823df08166c13ab042695b8dea8d1612dc7151d2457d7d2e6a69820309bf+5
debiandebian/linux< linux 6.1.133-1 (bookworm)

Patches

🔴Vulnerability Details

19
OSV
linux-oracle-6.8 vulnerabilities2025-10-15
OSV
linux-azure-nvidia vulnerabilities2025-10-08
OSV
linux-oracle vulnerabilities2025-10-06
OSV
linux-azure, linux-azure-6.8 vulnerabilities2025-10-02
OSV
linux-raspi-realtime vulnerabilities2025-10-02

📋Vendor Advisories

20
Ubuntu
Linux kernel (Oracle) vulnerabilities2025-10-15
Ubuntu
Linux kernel (Azure, N-Series) vulnerabilities2025-10-08
Ubuntu
Linux kernel (Oracle) vulnerabilities2025-10-06
Ubuntu
Linux kernel (Raspberry Pi Real-time) vulnerabilities2025-10-02
Ubuntu
Linux kernel (HWE) vulnerabilities2025-10-02