Vulnerability details
CVE-2026-99999
Linux Linux
ipv4: validate checksum_start before completing checksum
CVSS 3.1
9.3Critical
Official description
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.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 9.3Critical | 3.1 | CVEProject cvelistV5 (CNA) (Linux) | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| Linux | Linux | 2.6.27 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | f43798c27684ab925adde7d8acc34c78c6e50df8 ≤ v < 0fab003ef4698e0628060a45a48f14b43ba2a40a | CVEProject cvelistV5 (CNA) |
| Linux | Linux | f43798c27684ab925adde7d8acc34c78c6e50df8 ≤ v < 94524b7b32691de2e2ce162c04d6cbc9106e5cbf | CVEProject cvelistV5 (CNA) |
| Linux | Linux | f43798c27684ab925adde7d8acc34c78c6e50df8 ≤ v < a65f69e0f38ffbed1b128029e09097436416dc8b | CVEProject cvelistV5 (CNA) |
| Linux | Linux | f43798c27684ab925adde7d8acc34c78c6e50df8 ≤ v < a464d950f31c89565cbaae038cc60db04fe01956 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | f43798c27684ab925adde7d8acc34c78c6e50df8 ≤ v < f3e835af6226f1dd12160cbd696081e9b6155de0 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | f43798c27684ab925adde7d8acc34c78c6e50df8 ≤ v < c3e33464746166264334641dc850a36eef7e6326 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | f43798c27684ab925adde7d8acc34c78c6e50df8 ≤ v < 6785011f8b16abf40b1e9d8b2e332232b3e68822 | CVEProject cvelistV5 (CNA) |
| Linux | Linux | f43798c27684ab925adde7d8acc34c78c6e50df8 ≤ v < 32a8b0adaa18e52aaa0b246b5ffe683075354dbb | CVEProject cvelistV5 (CNA) |
References and advisories
11- https://git.kernel.org/stable/c/a464d950f31c89565cbaae038cc60db04fe01956
- https://git.kernel.org/stable/c/0fab003ef4698e0628060a45a48f14b43ba2a40a
- https://git.kernel.org/stable/c/94524b7b32691de2e2ce162c04d6cbc9106e5cbf
- https://git.kernel.org/stable/c/a65f69e0f38ffbed1b128029e09097436416dc8b
- https://git.kernel.org/stable/c/32a8b0adaa18e52aaa0b246b5ffe683075354dbb
- https://git.kernel.org/stable/c/f3e835af6226f1dd12160cbd696081e9b6155de0
- https://git.kernel.org/stable/c/c3e33464746166264334641dc850a36eef7e6326
- https://git.kernel.org/stable/c/6785011f8b16abf40b1e9d8b2e332232b3e68822
- https://pwn.ai/blog/pwnescape
- https://vercel.com/blog/findings-from-the-1-million-dollar-vercel-sandbox-challenge
- http://www.openwall.com/lists/oss-security/2026/10/15/5
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Details
- Published
- 2026-10-15
- Last updated
- 2026-10-24
- State
- Published
- Assigner (CNA)
- Linux
- Kolun priority
- 38 · Medium
Exploit prediction (EPSS)
0.78%
Probability of exploitation in 30 days
56.3%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- No
- Exploitation
- None
- Technical impact
- Total
Weaknesses (CWE)
- CWE-20Improper Input Validation