Answer in brief
CVE-2025-39980 records a Unknown severity vulnerability in nexthop: Forbid FDB status change while nexthop is in a group. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=38428d68719c454d269cb03b776d8a4b0ad66111 <e1e87ac0daacd51f522ecd1645cd76b5809303ed || >=38428d68719c454d269cb03b776d8a4b0ad66111 <0e7bfe7a268ccbd7859730c529161cafbf44637c || >=38428d68719c454d269cb03b776d8a4b0ad66111 <ec428fff792b7bd15b248dafca2e654b666b1304 || >=38428d68719c454d269cb03b776d8a4b0ad66111 <24046d31f6f92220852d393d510b6062843e3fbd || >=38428d68719c454d269cb03b776d8a4b0ad66111 <f0e49fd13afe9dea7a09a1c9537fd00cea22badb || >=38428d68719c454d269cb03b776d8a4b0ad66111 <8dd4aa0122885f710930de135af2adc4ccc3238f || >=38428d68719c454d269cb03b776d8a4b0ad66111 <390b3a300d7872cef9588f003b204398be69ce08 | e1e87ac0daacd51f522ecd1645cd76b5809303ed, 0e7bfe7a268ccbd7859730c529161cafbf44637c, ec428fff792b7bd15b248dafca2e654b666b1304, 24046d31f6f92220852d393d510b6062843e3fbd, f0e49fd13afe9dea7a09a1c9537fd00cea22badb, 8dd4aa0122885f710930de135af2adc4ccc3238f, 390b3a300d7872cef9588f003b204398be69ce08 |
| Linux/Linuxgeneric | 5.8 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.7 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.7 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.7 <* | * |
Published upstream
Oct 15, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
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
Quoted source text, attributed separately from HOL analysis.