Answer in brief
CVE-2026-68118 records a Unknown severity 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). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. 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 | >=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 |
Published upstream
Aug 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 10, 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.
Answer in brief
CVE-2026-68118 records a Unknown severity 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). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. 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 | >=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 |
Published upstream
Aug 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 10, 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.