Answer in brief
CVE-2026-53012 records a Unknown severity vulnerability in nexthop: fix IPv6 route referencing IPv4 nexthop. 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 1518F-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 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=7bf4796dd09984ad1612877a82d0d139c70ae27f <ceffe81a0be92afc0cd1340bc8ca46559cce9bb4 || >=7bf4796dd09984ad1612877a82d0d139c70ae27f <9c2d6770a5f4545a307eb66979bef7656a34d621 || >=7bf4796dd09984ad1612877a82d0d139c70ae27f <6275796f22bb382f3e9aa58ed0b4ef7bdad78cb8 || >=7bf4796dd09984ad1612877a82d0d139c70ae27f <aaac3bed034239e1d75732211d9b05f30b0b4f35 || >=7bf4796dd09984ad1612877a82d0d139c70ae27f <ad85961004fd4bd2f31209ac4b07612c6cefb9e7 || >=7bf4796dd09984ad1612877a82d0d139c70ae27f <613c8f4a501421dd258b07ea614205d4e16ec845 || >=7bf4796dd09984ad1612877a82d0d139c70ae27f <b3b7e850e1541f0520c4a12ec884255c30427ff6 || >=7bf4796dd09984ad1612877a82d0d139c70ae27f <29c95185ba32b621fbc3800fb86e7dc3edf5c2be | ceffe81a0be92afc0cd1340bc8ca46559cce9bb4, 9c2d6770a5f4545a307eb66979bef7656a34d621, 6275796f22bb382f3e9aa58ed0b4ef7bdad78cb8, aaac3bed034239e1d75732211d9b05f30b0b4f35, ad85961004fd4bd2f31209ac4b07612c6cefb9e7, 613c8f4a501421dd258b07ea614205d4e16ec845, b3b7e850e1541f0520c4a12ec884255c30427ff6, 29c95185ba32b621fbc3800fb86e7dc3edf5c2be |
| Linux/Linuxgeneric | 5.3 | Not reported |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
Published upstream
Jun 24, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 24, 2026
In the Linux kernel, the following vulnerability has been resolved: nexthop: fix IPv6 route referencing IPv4 nexthop syzbot reported a panic [1] [2]. When an IPv6 nexthop is replaced with an IPv4 nexthop, the has_v4 flag of all groups containing this nexthop is not updated. This is because nh_group_v4_update is only called when replacing AF_INET to AF_INET6, but the reverse direction (AF_INET6 to AF_INET) is missed. This allows a stale has_v4=false to bypass fib6_check_nexthop, causing IPv6 routes to be attached to groups that effectively contain only AF_INET members. Subsequent route lookups then call nexthop_fib6_nh() which returns NULL for the AF_INET member, leading to a NULL pointer dereference. Fix by calling nh_group_v4_update whenever the family changes, not just AF_INET to AF_INET6. Reproducer: # AF_INET6 blackhole ip -6 nexthop add id 1 blackhole # group with has_v4=false ip nexthop add id 100 group 1 # replace with AF_INET (no -6), has_v4 stays false ip nexthop replace id 1 blackhole # pass stale has_v4 check ip -6 route add 2001:db8::/64 nhid 100 # panic ping -6 2001:db8::1 [1] https://syzkaller.appspot.com/bug?id=e17283eb2f8dcf3dd9b47fe6f67a95f71faadad0 [2] https://syzkaller.appspot.com/bug?id=8699b6ae54c9f35837d925686208402949e12ef3
Quoted source text, attributed separately from HOL analysis.