Answer in brief
CVE-2026-98303 records a Unknown severity vulnerability in ipv4: icmp: reject RTN_UNREACHABLE input routes in icmp_route_lookup. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <06083cea4a3b95f5ebc85312f97d7086e6c9e782 || >=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <83aa83f81a8fec30ff5372dee60b2f0561bcb2ca || >=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <cac69c50716c712ef0114837c9427da66066124c || >=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <1af2d87964d87ba7626d96928d68c09158b5a223 || >=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <fda3000147dc96c75ba162f680bec0a9fecf3037 || >=8b7817f3a959ed99d7443afc12f78a7e1fcc2063 <2998147b59c9df0a51477c7a6b3d1f0ba3127dd4 | 06083cea4a3b95f5ebc85312f97d7086e6c9e782, 83aa83f81a8fec30ff5372dee60b2f0561bcb2ca, cac69c50716c712ef0114837c9427da66066124c, 1af2d87964d87ba7626d96928d68c09158b5a223, fda3000147dc96c75ba162f680bec0a9fecf3037, 2998147b59c9df0a51477c7a6b3d1f0ba3127dd4 |
| Linux/Linuxgeneric | 2.6.25 | Not reported |
Published upstream
Oct 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 6, 2026
In the Linux kernel, the following vulnerability has been resolved: ipv4: icmp: reject RTN_UNREACHABLE input routes in icmp_route_lookup When the forward output route cannot be used in icmp_route_lookup(), it enters the "reverse path" and calls ip_route_input() on fl4_dec.daddr, the original packet's source address. ip_route_input() only returns an error for truly invalid packets. For unreachable addresses it will succeed and return an input route whose dst.output is set to ip_rt_bug(). The existing check only rejects RTN_LOCAL routes, so the RTN_UNREACHABLE route types can still be returned and later used for output, syzkaller triggering a WARN_ON_ONCE() in ip_rt_bug() as bellow: ------------[ cut here ]------------ WARNING: net/ipv4/route.c:1273 at ip_rt_bug+0x14/0x20 RIP: 0010:ip_rt_bug+0x14/0x20 Call Trace: ip_push_pending_frames+0xfa/0x100 __icmp_send+0x905/0xf10 ip_options_compile+0xc0/0xd0 ip_rcv_finish_core+0x321/0xae0 ip_rcv+0x1de/0x260 __netif_receive_skb_one_core+0x11a/0x130 netif_receive_skb+0x7b/0x260 tun_get_user+0x11bf/0x1c10 ------------[ cut here ]------------ Reject input route that is RTN_UNREACHABLE to fix it. The net warning is only printed for RTN_LOCAL, as RTN_UNREACHABLE is not the result of a race condition.
Quoted source text, attributed separately from HOL analysis.