Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-72421— ipv4: fib: Don't ignore error route in local/main tables.

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会开源的一个操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于fib_lookup()执行路由查找时未正确退出，导致错误路由被默认表中的其他路由覆盖，可能引起路由选择不一致，造成非预期网络访问。

CVSS 10.0 · Critical EPSS 0.60% · P47

Possible ATT&CK Techniques 1 AI

T1044

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux f4530fa574df4d833506c53697ed1daa0d390bf4< a29e95fbc51e8a1b932773fd0e259b2080881443 affected
f4530fa574df4d833506c53697ed1daa0d390bf4< 5ae18d87a45698e8244d0fcba64c658c35a7dd3d affected
f4530fa574df4d833506c53697ed1daa0d390bf4< 9127589aabdee588278e8d0d0bd3709a760a92c8 affected
f4530fa574df4d833506c53697ed1daa0d390bf4< 49eaf1403201357762d745a35882fb734107d763 affected
f4530fa574df4d833506c53697ed1daa0d390bf4< fd25996f57a95d56bc568c89b4921edcf334b7d8 affected
f4530fa574df4d833506c53697ed1daa0d390bf4< 828fad4fd418bcdb9f5d66fec0d184c52a85ec31 affected
f4530fa574df4d833506c53697ed1daa0d390bf4< a668fa160247d7bbe921548cb845f607b8b9305f affected
f4530fa574df4d833506c53697ed1daa0d390bf4< b72f0db64205d9ce462038ba995d5d31eff32dc1 affected
… +10 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-72421

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
ipv4: fib: Don't ignore error route in local/main tables.
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: ipv4: fib: Don't ignore error route in local/main tables. When CONFIG_IP_MULTIPLE_TABLES is enabled but no rule is added, fib_lookup() performs route lookup directly on two tables. Since the first lookup does not properly bail out, the result of an error route in the merged local/main table could be overwritten by another route in the default table: # unshare -n # ip link set lo up # ip route add 192.168.0.0/24 dev lo table 253 # ip route add unreachable 192.168.0.0/24 # ip route get 192.168.0.1 192.168.0.1 dev lo table default uid 0 cache <local> Once a random rule is added, the error route is respected: # ip rule add table 0 # ip rule del table 0 # ip route get 192.168.0.1 RTNETLINK answers: No route to host Let's fix the inconsistent behaviour.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会开源的一个操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于fib_lookup()执行路由查找时未正确退出，导致错误路由被默认表中的其他路由覆盖，可能引起路由选择不一致，造成非预期网络访问。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux f4530fa574df4d833506c53697ed1daa0d390bf4 ~ a29e95fbc51e8a1b932773fd0e259b2080881443 -
Linux Linux 3.6 -

II. Public POCs for CVE-2026-72421

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-72421

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-72421 (7)

Other References for CVE-2026-72421 (1)

Same Patch Batch · Linux · 2026-08-15 · 844 CVEs total

CVE-2026-74279 10.0 CRITICAL crypto: cavium/cpt - fix DMA cleanup using wrong loop index
CVE-2026-74280 10.0 CRITICAL crypto: marvell/octeontx - fix DMA cleanup using wrong loop index
CVE-2026-74475 10.0 CRITICAL vxlan: use neigh_ha_snapshot() in route_shortcircuit()
CVE-2026-72408 10.0 CRITICAL geneve: gate GRO hint in geneve_gro_complete() on gs->gro_hint
CVE-2026-72407 10.0 CRITICAL geneve: validate inner network offset in geneve_gro_complete()
CVE-2026-74309 10.0 CRITICAL vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler
CVE-2026-72493 9.9 CRITICAL net: serialize netif_running() check in enqueue_to_backlog()
CVE-2026-72084 9.8 CRITICAL scsi: target: Bound PR-OUT TransportID parsing to the received buffer
CVE-2026-72191 9.8 CRITICAL ntfs3: validate split-point offset in indx_insert_into_buffer
CVE-2026-72083 9.8 CRITICAL scsi: target: core: Fix iSCSI ISID use-after-free in REGISTER AND MOVE
CVE-2026-74345 9.8 CRITICAL RDMA/siw: Fix endpoint/socket association handling
CVE-2026-72248 9.8 CRITICAL netfilter: flowtable: support IPIP tunnel with direct xmit
CVE-2026-72249 9.8 CRITICAL netfilter: flowtable: use dst in this direction when pushing IPIP header
CVE-2026-74493 9.8 CRITICAL net/smc: fix socket use-after-free during link group termination
CVE-2026-74495 9.8 CRITICAL igbvf: Fix leak in TX DMA error cleanup
CVE-2026-72251 9.8 CRITICAL netfilter: nf_nat_sip: reload possible stale data pointer
CVE-2026-74398 9.8 CRITICAL ipv6: addrconf: bail out of dad_failure when state is no longer POSTDAD
CVE-2026-74401 9.8 CRITICAL dlm: fix add msg handle in send_queue ordered
CVE-2026-74315 9.8 CRITICAL lockd: Avoid hashing uninitialized bytes in nlm4svc_lookup_file()
CVE-2026-72046 9.8 CRITICAL gve: fix header buffer corruption with header-split and HW-GRO

Showing top 20 of 844 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-72421

No comments yet

Leave a comment