7.5

CVE-2025-68241: linux

CVSS: 7.5v3.1HighDeferred
AliasesUBUNTU-CVE-2025-68241DEBIAN-CVE-2025-68241
Published 16-12-2025Last modified 05-08-2026
Open JSON

Vulnerability summary

CVE-2025-68241 is a high (CVSS 7.5) vulnerability in linux. EPSS estimates a 0.47% chance of exploitation in the next 30 days, higher than 39% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.47%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 41 · Related 38
DLA-4436-1MGASA-2026-0017MGASA-2026-0018OPENSUSE-SU-2026:20287-1SUSE-SU-2026:0447-1SUSE-SU-2026:0472-1

Timeline

  1. 16-12-2025
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: ipv4: route: Prevent rt_bind_exception() from rebinding stale fnhe The sit driver's packet transmission path calls: sit_tunnel_xmit() -> update_or_create_fnhe(), which lead to fnhe_remove_oldest() being called to delete entries exceeding FNHE_RECLAIM_DEPTH+random. The race window is between fnhe_remove_oldest() selecting fnheX for deletion and the subsequent kfree_rcu(). During this time, the concurrent path's __mkroute_output() -> find_exception() can fetch the soon-to-be-deleted fnheX, and rt_bind_exception() then binds it with a new dst using a dst_hold(). When the original fnheX is freed via RCU, the dst reference remains permanently leaked. CPU 0 CPU 1 __mkroute_output() find_exception() [fnheX] update_or_create_fnhe() fnhe_remove_oldest() [fnheX] rt_bind_exception() [bind dst] RCU callback [fnheX freed, dst leak] This issue manifests as a device reference count leak and a warning in dmesg when unregistering the net device: unregister_netdevice: waiting for sitX to become free. Usage count = N Ido Schimmel provided the simple test validation method [1]. The fix clears 'oldest->fnhe_daddr' before calling fnhe_flush_routes(). Since rt_bind_exception() checks this field, setting it to zero prevents the stale fnhe from being reused and bound to a new dst just before it is freed. [1] ip netns add ns1 ip -n ns1 link set dev lo up ip -n ns1 address add 192.0.2.1/32 dev lo ip -n ns1 link add name dummy1 up type dummy ip -n ns1 route add 192.0.2.2/32 dev dummy1 ip -n ns1 link add name gretap1 up arp off type gretap \ local 192.0.2.1 remote 192.0.2.2 ip -n ns1 route add 198.51.0.0/16 dev gretap1 taskset -c 0 ip netns exec ns1 mausezahn gretap1 \ -A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q & taskset -c 2 ip netns exec ns1 mausezahn gretap1 \ -A 198.51.100.1 -B 198.51.0.0/16 -t udp -p 1000 -c 0 -q & sleep 10 ip netns pids ns1 | xargs kill ip netns del ns1

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.47%

Chance of exploitation in the next 30 days

Percentile

39%

Versus all other CVEs

30-day change

0.00 pp

From 0.47% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.47%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu152 products
  • linuxAll versions (No fix recorded) | < 5.15.0-173.183 | < 6.8.0-106.106 | < 6.17.0-14.14
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1103.110 | < 6.8.0-1050.53 | < 6.17.0-1007.7
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.1.159-1 | < 6.12.63-1 | < 6.17.9-1
Linux1 product
  • linux≥ e46e23c289f62ccd8e2230d9ce652072d777ff30, < 69d35c12168f9c59b159ae566f77dfad9f96d7ca | ≥ 5867e20e1808acd0c832ddea2587e5ee49813874, < 4b7210da22429765d19460d38c30eeca72656282 | ≥ 67d6d681e15b578c1725bad8ad079e05d1c48a8e, < 298f1e0694ab4edb6092d66efed93c4554e6ced1 | ≥ 67d6d681e15b578c1725bad8ad079e05d1c48a8e, < b8a44407bdaf2f0c5505cc7d9fc7d8da90cf9a94 | ≥ 67d6d681e15b578c1725bad8ad079e05d1c48a8e, < 041ab9ca6e80d8f792bb69df28ebf1ef39c06af8 | ≥ 67d6d681e15b578c1725bad8ad079e05d1c48a8e, < b84f083f50ecc736a95091691339a1b363962f0e | ≥ 67d6d681e15b578c1725bad8ad079e05d1c48a8e, < 0fd16ed6dc331636fb2a874c42d2f7d3156f7ff0 | ≥ 67d6d681e15b578c1725bad8ad079e05d1c48a8e, < ac1499fcd40fe06479e9b933347b837ccabc2a40 | bed8941fbdb72a61f6348c4deb0db69c4de87aca | f10ce783bcc4d8ea454563a7d56ae781640e7dcb | f484595be6b7ef9d095a32becabb5dae8204fb2a | 3e6bd2b583f18da9856fc9741ffa200a74a52cba | 5ae06218331f39ec45b5d039aa7cb3ddd4bb8008 | 4589a12dcf80af31137ef202be1ff4a321707a73 | ≥ 5.4.146, < 5.4.302 | ≥ 5.10.65, < 5.10.247 | ≥ 4.4.284, < 4.5 | ≥ 4.9.283, < 4.10 | ≥ 4.14.247, < 4.15 | ≥ 4.19.207, < 4.20 | ≥ 5.13.17, < 5.14 | ≥ 5.14.4, < 5.15 | 5.15

3 vendors · 154 products

References

37 links
Show all 37 references