by Kastro
Paper/Archive/CVE-2026-99999

CVE-2026-99999

Linux Linux — ipv4: validate checksum_start before completing checksum

EPSS 0.8%CVSS 9.3
critical.is priorityof 100
39
CVSS 9.3 (CNA)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 56.1.561 × 2011.2No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

In the Linux kernel, the following vulnerability has been resolved: ipv4: validate checksum_start before completing checksum If a packet with bad checksum metadata gets into the ipv4 stack, skb_checksum_help can corrupt the network header and cause a bunch of mischief. This was discovered and reported by Paulos, and has been reporoduced by others independently since. We really shouldn't allow such packets in, but as a defence in depth measure, let's also check before we complete the checksum. A more complete validation at input is forthcoming, but needs more work.

Affected

ProductAffectedFixed inSource
Linuxf43798c27684ab925adde7d8acc34c78c6e50df8 – < a464d950f31c89565cbaae038cc60db04fe01956a464d950f31c89565cbaae038cc60db04fe01956CNA
Linuxf43798c27684ab925adde7d8acc34c78c6e50df8 – < 0fab003ef4698e0628060a45a48f14b43ba2a40a0fab003ef4698e0628060a45a48f14b43ba2a40aCNA
Linuxf43798c27684ab925adde7d8acc34c78c6e50df8 – < 94524b7b32691de2e2ce162c04d6cbc9106e5cbf94524b7b32691de2e2ce162c04d6cbc9106e5cbfCNA
Linuxf43798c27684ab925adde7d8acc34c78c6e50df8 – < a65f69e0f38ffbed1b128029e09097436416dc8ba65f69e0f38ffbed1b128029e09097436416dc8bCNA
Linuxf43798c27684ab925adde7d8acc34c78c6e50df8 – < 32a8b0adaa18e52aaa0b246b5ffe683075354dbb32a8b0adaa18e52aaa0b246b5ffe683075354dbbCNA
Linuxf43798c27684ab925adde7d8acc34c78c6e50df8 – < f3e835af6226f1dd12160cbd696081e9b6155de0f3e835af6226f1dd12160cbd696081e9b6155de0CNA
Linuxf43798c27684ab925adde7d8acc34c78c6e50df8 – < c3e33464746166264334641dc850a36eef7e6326c3e33464746166264334641dc850a36eef7e6326CNA
Linuxf43798c27684ab925adde7d8acc34c78c6e50df8 – < 6785011f8b16abf40b1e9d8b2e332232b3e688226785011f8b16abf40b1e9d8b2e332232b3e68822CNA
Linux2.6.27–CNA

Scores by source

Linux (CNA)9.3CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

refgit.kernel.org/stable/c/a464d950f31c89565cbaae038cc60db04fe01956refgit.kernel.org/stable/c/0fab003ef4698e0628060a45a48f14b43ba2a40arefgit.kernel.org/stable/c/94524b7b32691de2e2ce162c04d6cbc9106e5cbfrefgit.kernel.org/stable/c/a65f69e0f38ffbed1b128029e09097436416dc8brefgit.kernel.org/stable/c/32a8b0adaa18e52aaa0b246b5ffe683075354dbbrefgit.kernel.org/stable/c/f3e835af6226f1dd12160cbd696081e9b6155de0refgit.kernel.org/stable/c/c3e33464746166264334641dc850a36eef7e6326refgit.kernel.org/stable/c/6785011f8b16abf40b1e9d8b2e332232b3e68822refpwn.ai/blog/pwnescaperefvercel.com/blog/findings-from-the-1-million-dollar-vercel-sandbox-challengerefopenwall.com/lists/oss-security/2026/10/15/5