Answer in brief
CVE-2026-68118 records a High severity (CVSS 8.2) vulnerability in tcp: challenge ACK for non-exact RST in SYN-RECEIVED. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), 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 8.2. 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), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=282f23c6ee343126156dd41218b22ece96d747e3 <234f9ffbd9b2c1b24ec67200ea3cff07401bec48 || >=282f23c6ee343126156dd41218b22ece96d747e3 <22cec809b048495310f206d9abbcdbbfbdce3ae3 || >=282f23c6ee343126156dd41218b22ece96d747e3 <a28c4fcbf774e23b4779cae468e3497a5ad1f4a1 || 86791bbfe5ed7b275be040cfeff049a1624af1b7 || 61f69dc4e40e41b0018f00fa4aeb23d3239556fb || 34fb350281ced2a72707a5c0064f69992d440edb || >=3.0.58 <3.1 || >=3.2.37 <3.3 || >=3.4.25 <3.5 | 234f9ffbd9b2c1b24ec67200ea3cff07401bec48, 22cec809b048495310f206d9abbcdbbfbdce3ae3, a28c4fcbf774e23b4779cae468e3497a5ad1f4a1, 3.1, 3.3, 3.5 |
| Linux/Linuxgeneric | 3.6 | Not reported |
| Linux/Linuxgeneric | >=282f23c6ee343126156dd41218b22ece96d747e3 <8b0a3a094f4cae2fb92e4d08d4eef7246a9d9c49 || >=282f23c6ee343126156dd41218b22ece96d747e3 <0fe4636665d14a258de70b4f3e8248e6d42038f1 || >=282f23c6ee343126156dd41218b22ece96d747e3 <234f9ffbd9b2c1b24ec67200ea3cff07401bec48 || >=282f23c6ee343126156dd41218b22ece96d747e3 <22cec809b048495310f206d9abbcdbbfbdce3ae3 || >=282f23c6ee343126156dd41218b22ece96d747e3 <a28c4fcbf774e23b4779cae468e3497a5ad1f4a1 || 86791bbfe5ed7b275be040cfeff049a1624af1b7 || 61f69dc4e40e41b0018f00fa4aeb23d3239556fb || 34fb350281ced2a72707a5c0064f69992d440edb || >=3.0.58 <3.1 || >=3.2.37 <3.3 || >=3.4.25 <3.5 | 8b0a3a094f4cae2fb92e4d08d4eef7246a9d9c49, 0fe4636665d14a258de70b4f3e8248e6d42038f1, 234f9ffbd9b2c1b24ec67200ea3cff07401bec48, 22cec809b048495310f206d9abbcdbbfbdce3ae3, a28c4fcbf774e23b4779cae468e3497a5ad1f4a1, 3.1, 3.3, 3.5 |
| Linux/Linuxgeneric | >=282f23c6ee343126156dd41218b22ece96d747e3 <c5dc463cc60eb26079b19607c9dbda76491dad05 || >=282f23c6ee343126156dd41218b22ece96d747e3 <8b0a3a094f4cae2fb92e4d08d4eef7246a9d9c49 || >=282f23c6ee343126156dd41218b22ece96d747e3 <0fe4636665d14a258de70b4f3e8248e6d42038f1 || >=282f23c6ee343126156dd41218b22ece96d747e3 <234f9ffbd9b2c1b24ec67200ea3cff07401bec48 || >=282f23c6ee343126156dd41218b22ece96d747e3 <22cec809b048495310f206d9abbcdbbfbdce3ae3 || >=282f23c6ee343126156dd41218b22ece96d747e3 <a28c4fcbf774e23b4779cae468e3497a5ad1f4a1 || 86791bbfe5ed7b275be040cfeff049a1624af1b7 || 61f69dc4e40e41b0018f00fa4aeb23d3239556fb || 34fb350281ced2a72707a5c0064f69992d440edb || >=3.0.58 <3.1 || >=3.2.37 <3.3 || >=3.4.25 <3.5 | c5dc463cc60eb26079b19607c9dbda76491dad05, 8b0a3a094f4cae2fb92e4d08d4eef7246a9d9c49, 0fe4636665d14a258de70b4f3e8248e6d42038f1, 234f9ffbd9b2c1b24ec67200ea3cff07401bec48, 22cec809b048495310f206d9abbcdbbfbdce3ae3, a28c4fcbf774e23b4779cae468e3497a5ad1f4a1, 3.1, 3.3, 3.5 |
Published upstream
Aug 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 10, 2026
In the Linux kernel, the following vulnerability has been resolved: tcp: challenge ACK for non-exact RST in SYN-RECEIVED The SYN-RECEIVED request-socket path in tcp_check_req() accepts an in-window RST without requiring SEG.SEQ to exactly match RCV.NXT. A non-exact RST therefore removes the request instead of eliciting a challenge ACK. RFC 9293 section 3.10.7.4 applies the RFC 5961 reset check in SYN-RECEIVED: an exact RST resets the connection, while a non-exact in-window RST must trigger a challenge ACK and be dropped. Apply that check before the ACK-field validation, following the RFC sequence-number, RST, then ACK processing order. Factor the per-netns challenge ACK quota out of tcp_send_challenge_ack() so request sockets can share it. Use the request socket's send_ack() callback and its own out-of-window ACK timestamp to send and rate-limit the response.
Quoted source text, attributed separately from HOL analysis.