CVE-2025-39980: linux
Vulnerability summary
CVE-2025-39980 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.23% chance of exploitation in the next 30 days, higher than 13.3% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 44 · Related 39Timeline
- 15-10-2025PublishedVulnerability first disclosed.
- 15-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: nexthop: Forbid FDB status change while nexthop is in a group The kernel forbids the creation of non-FDB nexthop groups with FDB nexthops: # ip nexthop add id 1 via 192.0.2.1 fdb # ip nexthop add id 2 group 1 Error: Non FDB nexthop group cannot have fdb nexthops. And vice versa: # ip nexthop add id 3 via 192.0.2.2 dev dummy1 # ip nexthop add id 4 group 3 fdb Error: FDB nexthop group can only have fdb nexthops. However, as long as no routes are pointing to a non-FDB nexthop group, the kernel allows changing the type of a nexthop from FDB to non-FDB and vice versa: # ip nexthop add id 5 via 192.0.2.2 dev dummy1 # ip nexthop add id 6 group 5 # ip nexthop replace id 5 via 192.0.2.2 fdb # echo $? 0 This configuration is invalid and can result in a NPD [1] since FDB nexthops are not associated with a nexthop device: # ip route add 198.51.100.1/32 nhid 6 # ping 198.51.100.1 Fix by preventing nexthop FDB status change while the nexthop is in a group: # ip nexthop add id 7 via 192.0.2.2 dev dummy1 # ip nexthop add id 8 group 7 # ip nexthop replace id 7 via 192.0.2.2 fdb Error: Cannot change nexthop FDB status while in a group. [1] BUG: kernel NULL pointer dereference, address: 00000000000003c0 [...] Oops: Oops: 0000 [#1] SMP CPU: 6 UID: 0 PID: 367 Comm: ping Not tainted 6.17.0-rc6-virtme-gb65678cacc03 #1 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014 RIP: 0010:fib_lookup_good_nhc+0x1e/0x80 [...] Call Trace: <TASK> fib_table_lookup+0x541/0x650 ip_route_output_key_hash_rcu+0x2ea/0x970 ip_route_output_key_hash+0x55/0x80 __ip4_datagram_connect+0x250/0x330 udp_connect+0x2b/0x60 __sys_connect+0x9c/0xd0 __x64_sys_connect+0x18/0x20 do_syscall_64+0xa4/0x2a0 entry_SYSCALL_64_after_hwframe+0x4b/0x53
CVSS metrics
Risk metrics not yet published.
EPSS trend
Probability
0.23%
Chance of exploitation in the next 30 days
Percentile
13%
Versus all other CVEs
30-day change
+0.02 pp
From 0.21% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu135 products
- linux< 5.15.0-170.180 | < 6.8.0-106.106 | < 6.17.0-6.6
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 5.15.0-1100.107 | < 6.8.0-1050.53 | < 6.17.0-1003.3
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian1 product
- linux< 6.1.158-1 | < 6.12.57-1 | < 6.16.10-1
Linux1 product
- linux≥ 38428d68719c454d269cb03b776d8a4b0ad66111, < e1e87ac0daacd51f522ecd1645cd76b5809303ed | ≥ 38428d68719c454d269cb03b776d8a4b0ad66111, < 0e7bfe7a268ccbd7859730c529161cafbf44637c | ≥ 38428d68719c454d269cb03b776d8a4b0ad66111, < ec428fff792b7bd15b248dafca2e654b666b1304 | ≥ 38428d68719c454d269cb03b776d8a4b0ad66111, < 24046d31f6f92220852d393d510b6062843e3fbd | ≥ 38428d68719c454d269cb03b776d8a4b0ad66111, < f0e49fd13afe9dea7a09a1c9537fd00cea22badb | ≥ 38428d68719c454d269cb03b776d8a4b0ad66111, < 8dd4aa0122885f710930de135af2adc4ccc3238f | ≥ 38428d68719c454d269cb03b776d8a4b0ad66111, < 390b3a300d7872cef9588f003b204398be69ce08 | 5.8
3 vendors · 137 products
