CVE-2025-71080 [Medium] | Security Vulnerability in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT On PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the current task can be preempted. Another task running on the same CPU may then execute rt6_make_pcpu_route() and successfully install a pcpu_rt entry. When the first task resumes execution, its cmpxchg() in rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer NULL, triggering the BUG_ON(prev). It's easy to reproduce it by adding mdelay() after rt6_get_pcpu_route(). Using preempt_disable/enable is not appropriate here because ip6_rt_pcpu_alloc() may sleep. Fix this by handling the cmpxchg() failure gracefully on PREEMPT_RT: free our allocation and return the existing pcpu_rt installed by another task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT kernels where such races should not occur.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.02%	0.12%	+0.10%
2	2026-01-14	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.02%

0.12%

+0.10%

2026-01-14

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.5	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. 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:L) A normal user session is enough; they don’t have to be admin. 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:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.5

3.1

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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:L): A normal user session is enough; they don’t have to be admin.
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:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

3.6

[email protected]

OS Trackers for CVE-2025-71080

vendor	priority	summary	link
`debian`	unimportant	CVE-2025-71080 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2025-71080
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2025-71080
`suse`	low	CVE-2025-71080 severity low: SUSE including 372 source package names (13.2-9.1:libsqlite3-0-3.49.1-1.1, 2.1.3-6.31:libsqlite3-0-3.49.1-1.1, …), 685 product×package rows across 81 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (81 product lines)): Fixed 238, Known Affected 231, Known Not Affected 191, First Fixed 25.	https://www.suse.com/security/cve/CVE-2025-71080/
`ubuntu`	medium	CVE-2025-71080 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1405 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1010, ignored 174, not-affected 126, released 93, pending 2.	https://ubuntu.com/security/CVE-2025-71080

Affected software / configurations for CVE-2025-71080

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 6.12.1, < 6.12.64	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.13, < 6.18.4	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	6.12	cpe:2.3:o:linux:linux_kernel:6.12:-::::::
linux	linux_kernel	6.19	cpe:2.3:o:linux:linux_kernel:6.19:rc1::::::
linux	linux_kernel	6.19	cpe:2.3:o:linux:linux_kernel:6.19:rc2::::::
linux	linux_kernel	6.19	cpe:2.3:o:linux:linux_kernel:6.19:rc3::::::
linux	linux_kernel	6.19	cpe:2.3:o:linux:linux_kernel:6.19:rc4::::::
linux	linux_kernel	6.19	cpe:2.3:o:linux:linux_kernel:6.19:rc5::::::
linux	linux_kernel	6.19	cpe:2.3:o:linux:linux_kernel:6.19:rc6::::::
linux	linux_kernel	6.19	cpe:2.3:o:linux:linux_kernel:6.19:rc7::::::
linux	linux_kernel	6.19	cpe:2.3:o:linux:linux_kernel:6.19:rc8::::::

References for CVE-2025-71080

URL	Tags
https://git.kernel.org/stable/c/1adaea51c61b52e24e7ab38f7d3eba023b2d050d	Patch
https://git.kernel.org/stable/c/1dc33ad0867325f8d2c6d7b2a6f542d4f3121f66	Patch
https://git.kernel.org/stable/c/787515ccb2292f82eb0876993129154629a49651	Patch

URL

CVE-2025-71080 | ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT

Exploit prediction scoring system (EPSS) score for CVE-2025-71080

Common vulnerability scoring system (CVSS) metrics for CVE-2025-71080

Weakness enumeration for CVE-2025-71080

OS Trackers for CVE-2025-71080

Affected software / configurations for CVE-2025-71080

References for CVE-2025-71080