Answer in brief
CVE-2026-23304 records a Medium severity (CVSS 5.5) vulnerability in ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu(). 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.
Answer in brief
CVE-2026-23304 records a Medium severity (CVSS 5.5) vulnerability in ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu(). 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.
CVSS is 5.5. 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 | >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <d542e2ac7f9e288d49735be0775611547ca4e0ee || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <4a48fe59f29f673a3d042d679f26629a9c3e29d4 || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <581800298313c9fd75e94985e6d37d21b7e35d34 || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <3310fc11fc47387d1dd4759b0bc961643ea11c7f || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <0b5a7826020706057cc5a9d9009e667027f221ee || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <ae88c8256547b63980770a9ea7be73a15900d27e || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a | d542e2ac7f9e288d49735be0775611547ca4e0ee, a73fe9f4ae84a239d5b2686f47a58c158aee2eb4, 4a48fe59f29f673a3d042d679f26629a9c3e29d4, 581800298313c9fd75e94985e6d37d21b7e35d34, 3310fc11fc47387d1dd4759b0bc961643ea11c7f, 0b5a7826020706057cc5a9d9009e667027f221ee, ae88c8256547b63980770a9ea7be73a15900d27e, 2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a |
| Linux/Linuxgeneric | 4.14 | 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 | >=V3.1.5 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
Published upstream
Mar 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 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: ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu() l3mdev_master_dev_rcu() can return NULL when the slave device is being un-slaved from a VRF. All other callers deal with this, but we lost the fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu() with commit 4832c30d5458 ("net: ipv6: put host and anycast routes on device with address"). KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f] RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418) Call Trace: ip6_pol_route (net/ipv6/route.c:2318) fib6_rule_lookup (net/ipv6/fib6_rules.c:115) ip6_route_output_flags (net/ipv6/route.c:2607) vrf_process_v6_outbound (drivers/net/vrf.c:437) I was tempted to rework the un-slaving code to clear the flag first and insert synchronize_rcu() before we remove the upper. But looks like the explicit fallback to loopback_dev is an established pattern. And I guess avoiding the synchronize_rcu() is nice, too.
Quoted source text, attributed separately from HOL analysis.
CVSS is 5.5. 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 | >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <d542e2ac7f9e288d49735be0775611547ca4e0ee || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <a73fe9f4ae84a239d5b2686f47a58c158aee2eb4 || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <4a48fe59f29f673a3d042d679f26629a9c3e29d4 || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <581800298313c9fd75e94985e6d37d21b7e35d34 || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <3310fc11fc47387d1dd4759b0bc961643ea11c7f || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <0b5a7826020706057cc5a9d9009e667027f221ee || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <ae88c8256547b63980770a9ea7be73a15900d27e || >=4832c30d5458387ff2533ff66fbde26ad8bb5a2d <2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a | d542e2ac7f9e288d49735be0775611547ca4e0ee, a73fe9f4ae84a239d5b2686f47a58c158aee2eb4, 4a48fe59f29f673a3d042d679f26629a9c3e29d4, 581800298313c9fd75e94985e6d37d21b7e35d34, 3310fc11fc47387d1dd4759b0bc961643ea11c7f, 0b5a7826020706057cc5a9d9009e667027f221ee, ae88c8256547b63980770a9ea7be73a15900d27e, 2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a |
| Linux/Linuxgeneric | 4.14 | 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 | >=V3.1.5 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.5 <* | * |
Published upstream
Mar 25, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 14, 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: ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu() l3mdev_master_dev_rcu() can return NULL when the slave device is being un-slaved from a VRF. All other callers deal with this, but we lost the fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu() with commit 4832c30d5458 ("net: ipv6: put host and anycast routes on device with address"). KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f] RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418) Call Trace: ip6_pol_route (net/ipv6/route.c:2318) fib6_rule_lookup (net/ipv6/fib6_rules.c:115) ip6_route_output_flags (net/ipv6/route.c:2607) vrf_process_v6_outbound (drivers/net/vrf.c:437) I was tempted to rework the un-slaving code to clear the flag first and insert synchronize_rcu() before we remove the upper. But looks like the explicit fallback to loopback_dev is an established pattern. And I guess avoiding the synchronize_rcu() is nice, too.
Quoted source text, attributed separately from HOL analysis.