Answer in brief
CVE-2026-99999 records a Critical severity (CVSS 9.3) vulnerability in ipv4: validate checksum_start before completing checksum. 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.
CVSS is 9.3. 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 | >=f43798c27684ab925adde7d8acc34c78c6e50df8 <a464d950f31c89565cbaae038cc60db04fe01956 || >=f43798c27684ab925adde7d8acc34c78c6e50df8 <0fab003ef4698e0628060a45a48f14b43ba2a40a || >=f43798c27684ab925adde7d8acc34c78c6e50df8 <94524b7b32691de2e2ce162c04d6cbc9106e5cbf || >=f43798c27684ab925adde7d8acc34c78c6e50df8 <a65f69e0f38ffbed1b128029e09097436416dc8b || >=f43798c27684ab925adde7d8acc34c78c6e50df8 <32a8b0adaa18e52aaa0b246b5ffe683075354dbb || >=f43798c27684ab925adde7d8acc34c78c6e50df8 <f3e835af6226f1dd12160cbd696081e9b6155de0 || >=f43798c27684ab925adde7d8acc34c78c6e50df8 <c3e33464746166264334641dc850a36eef7e6326 || >=f43798c27684ab925adde7d8acc34c78c6e50df8 <6785011f8b16abf40b1e9d8b2e332232b3e68822 | a464d950f31c89565cbaae038cc60db04fe01956, 0fab003ef4698e0628060a45a48f14b43ba2a40a, 94524b7b32691de2e2ce162c04d6cbc9106e5cbf, a65f69e0f38ffbed1b128029e09097436416dc8b, 32a8b0adaa18e52aaa0b246b5ffe683075354dbb, f3e835af6226f1dd12160cbd696081e9b6155de0, c3e33464746166264334641dc850a36eef7e6326, 6785011f8b16abf40b1e9d8b2e332232b3e68822 |
| Linux/Linuxgeneric | 2.6.27 | Not reported |
Published upstream
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 15, 2026
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.
Quoted source text, attributed separately from HOL analysis.