high 7.1

CVE-2025-21719 json

ipmr: do not call mr_mfc_uses_dev() for unres entries

published 2025-02-27 20 mo ago modified 2026-10-15 24 d ago also EUVD-2025-5224

cvss: 7.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 10%
public exploits: 0; none known

In the Linux kernel, the following vulnerability has been resolved:

syzbot found that calling mr_mfc_uses_dev() for unres entries would crash [1], because c->mfc_un.res.minvif / c->mfc_un.res.maxvif alias to "struct sk_buff_head unresolved", which contain two pointers.

This code never worked, lets remove it.

[1] Unable to handle kernel paging request at virtual address ffff5fff2d536613 KASAN: maybe wild-memory-access in range [0xfffefff96a9b3098-0xfffefff96a9b309f] Modules linked in: CPU: 1 UID: 0 PID: 7321 Comm: syz.0.16 Not tainted 6.13.0-rc7-syzkaller-g1950a0af2d55 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : mr_mfc_uses_dev net/ipv4/ipmr_base.c:290 [inline] pc : mr_table_dump+0x5a4/0x8b0 net/ipv4/ipmr_base.c:334 lr : mr_mfc_uses_dev net/ipv4/ipmr_base.c:289 [inline] lr : mr_table_dump+0x694/0x8b0 net/ipv4/ipmr_base.c:334 Call trace: mr_mfc_uses_dev net/ipv4/ipmr_base.c:290 [inline] (P) mr_table_dump+0x5a4/0x8b0 net/ipv4/ipmr_base.c:334 (P) mr_rtm_dumproute+0x254/0x454 net/ipv4/ipmr_base.c:382 ipmr_rtm_dumproute+0x248/0x4b4 net/ipv4/ipmr.c:2648 rtnl_dump_all+0x2e4/0x4e8 net/core/rtnetlink.c:4327 rtnl_dumpit+0x98/0x1d0 net/core/rtnetlink.c:6791 netlink_dump+0x4f0/0xbc0 net/netlink/af_netlink.c:2317 netlink_recvmsg+0x56c/0xe64 net/netlink/af_netlink.c:1973 sock_recvmsg_nosec net/socket.c:1033 [inline] sock_recvmsg net/socket.c:1055 [inline] sock_read_iter+0x2d8/0x40c net/socket.c:1125 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x740/0x970 fs/read_write.c:565 ksys_read+0x15c/0x26c fs/read_write.c:708

Patch / fix

fixed in 1 distros 3 links 8

Linux Linux 5.4.291, 5.10.235, 5.15.179, 6.1.129, 6.6.76, 6.12.13, 6.13.2, 6.14

debian ubuntu suse

linux Debian 12 6.1.129-1
linux Debian 14, Debian 13 6.12.13-1

debian advisories DEBIAN-CVE-2025-21719

linux Ubuntu 20.04 LTS 5.4.0-216.236
linux Ubuntu 22.04 LTS 5.15.0-140.150
linux Ubuntu 24.04 LTS 6.8.0-64.67
linux-aws Ubuntu 20.04 LTS 5.4.0-1146.156
linux-aws Ubuntu 22.04 LTS 5.15.0-1084.91
linux-aws Ubuntu 24.04 LTS 6.8.0-1032.34
linux-gcp Ubuntu 20.04 LTS 5.4.0-1149.158
linux-gcp Ubuntu 22.04 LTS 5.15.0-1083.92

ubuntu advisories UBUNTU-CVE-2025-21719

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

kernel-coco SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.21.coco15sp6.1
kernel-syms-coco SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.21.coco15sp6.1
kernel-coco_debug SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.21.coco15sp6.1
kernel-source-coco SLE Module for Confidential Computing Technical Preview 15 SP6 6.4.0-15061.21.coco15sp6.1
kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1
kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-28.1.21.6

suse advisories SUSE-SU-2025:01919-1 SUSE-SU-2025:20192-1 SUSE-SU-2025:20270-1 SUSE-SU-2025:20190-1 SUSE-SU-2025:20260-1 SUSE-SU-2025:0955-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-21719 updated 2026-11-07 cvss 4.7

kernel: ipmr: do not call mr_mfc_uses_dev() for unres entries

Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
affected: no fix planned “Out of support scope”
Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
affected: no fix available “Fix deferred”
Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

cisa ICSA-26-295-16 updated 2026-10-22 cvss 7.1

Siemens SIMATIC S7-1500 TM MFP

Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-24-102-01 updated 2026-05-14 cvss 5.5

Siemens SIMATIC S7-1500 TM MFP

Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 24 d ago (2026-10-15)

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 10% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
NVD	3.1	7.1	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected products

Linux Linux
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem

Classification

Weakness

CWE-125 Out-of-bounds Read

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2025-21719
NVD CVE-2025-21719

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary