High · CVSS 7.5CVE-2026-31638

rxrpc: Only put the call ref if one was acquiredCVE-2026-31638

Answer in brief

CVE-2026-31638 records a High severity (CVSS 7.5) vulnerability in rxrpc: Only put the call ref if one was acquired. 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.

Published Apr 24, 2026Updated Oct 16, 2026Source checked Oct 16, 2026First seen by HOL Oct 16, 2026Material review Oct 16, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.5. 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.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=5e6ef4f1017c7f844e305283bbd8875af475e2fc <b8f66447448d6c305a51413a67ec8ed26aa7d1dd \|\| >=5e6ef4f1017c7f844e305283bbd8875af475e2fc <0c156aff8a2d4fa0d61db7837641975cf0e5452d \|\| >=5e6ef4f1017c7f844e305283bbd8875af475e2fc <8299ca146489664e3c0c90a3b8900d8335b1ede4 \|\| >=5e6ef4f1017c7f844e305283bbd8875af475e2fc <9fb09861e2b8d1abfe2efaf260c9f1d30080ea38 \|\| >=5e6ef4f1017c7f844e305283bbd8875af475e2fc <6331f1b24a3e85465f6454e003a3e6c22005a5c5	b8f66447448d6c305a51413a67ec8ed26aa7d1dd, 0c156aff8a2d4fa0d61db7837641975cf0e5452d, 8299ca146489664e3c0c90a3b8900d8335b1ede4, 9fb09861e2b8d1abfe2efaf260c9f1d30080ea38, 6331f1b24a3e85465f6454e003a3e6c22005a5c5
Linux/Linuxgeneric	6.2	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to b8f66447448d6c305a51413a67ec8ed26aa7d1dd if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Apr 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 16, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Only put the call ref if one was acquired rxrpc_input_packet_on_conn() can process a to-client packet after the current client call on the channel has already been torn down. In that case chan->call is NULL, rxrpc_try_get_call() returns NULL and there is no reference to drop. The client-side implicit-end error path does not account for that and unconditionally calls rxrpc_put_call(). This turns a protocol error path into a kernel crash instead of rejecting the packet. Only drop the call reference if one was actually acquired. Keep the existing protocol error handling unchanged.

Quoted source text, attributed separately from HOL analysis.