[CVE-2026-46000][MODERATE 7.0] rxrpc: Fix conn-level packet handling to unshare RESPONSE packets [ Upstream

[CVE-2026-46000][MODERATE 7.0] rxrpc: Fix conn-level packet handling to unshare RESPONSE packets [ Upstream

[AL-KERNEL]

CVE: CVE-2026-46000
Priority: MODERATE 7.0
AL-KERNEL base severity: MODERATE
KPANIC flag: NO
Patch: rxrpc: Fix conn-level packet handling to unshare RESPONSE packets [ Upstream
Commit: c0428a22daf69714dc042b67ea759956b74c74e5
Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c0428a22daf69714dc042b67ea759956b74c74e5
Original CVE announcement: https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46000
Analysis date: Wed, 27 May 2026 17:24:03 -0400
ActionableScore: 5
ActionableScore lower bound: 2
Actionable bucket: Actionable Moderate at minimum
Manual review required: NO

Summary:
No one-sentence report phrase was found.

======================================================================
ABOUT THIS REPORT
======================================================================

The original Linux kernel CVE announcement for CVE-2026-46000 is available here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46000

The original announcement does not normally provide a security severity
estimate, CVSS assessment, or enough information to determine whether the
reported kernel bug represents a practically relevant security issue.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin. It combines
an autonomous classifier with LLM-assisted technical analysis and a
separate ActionableScore mechanism.

The purpose of this report is to prioritize Linux kernel CVEs before
manual review, identify cases that require prompt investigation, and
support automatic closure of issues that are unlikely to have meaningful
security impact.

Published priority for this report: MODERATE 7.0
Manual review required: NO

A detailed explanation of the methodology and priority rules is included
at the end of this message.

======================================================================
AL-KERNEL CLASSIFICATION RESULT
======================================================================

CVE-2026-46000	MODERATE	CHECK	Maybe valid. Check manually. Hints by AL-KERNEL: The best (paranoid) CVSS is 'AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N';*CWE-200;CWE-668;*CWE-664;CWE-703;Other CVSS 'AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N';BEST CVSS score: '3.3';DESCR 'RXRPC RESPONSE verification can decrypt packet data in place while the skb is cloned and shared with a packet sniffer. A local sniffer may then observe partially decrypted or corrupted RESPONSE packet contents instead of the original encrypted packet. For the CVSS the PR:L is used in the paranoid score because packet capture may be delegated through CAP_NET_RAW or similar reduced privileges, although typical packet sniffing is still privileged. The issue is not a direct remote compromise path because the remote peer does not receive the decrypted data. Impact is limited confidentiality exposure to a local packet observer, with no supported kernel memory corruption or privilege escalation primitive.';YES REQUIRES MANUAL CHECK; ,and ActionableScore result is Actionable Moderate at minimum (with actual score 4) 	MAYBE	INIT TRACE NOMEMCHK SKB LINUS PACKET  INCREASED_FROM_LOW_BASED_ON_REQUIREMANUALCHECK DECREASED_TO_MODERATEREG_BASED_ON_ACTIONABLESCORELESSTHAN5	-	-	checked

======================================================================
ACTIONABLESCORE ANALYSIS
======================================================================

ActionableScore=5
ActionableScoreLower=2

1. ActionableScore
* Conservative score: 2
* Paranoid score: 5
* Final recommended bucket: **Actionable Moderate at minimum**::

2. Signal breakdown
* Confidentiality impact plausible: +1. A local packet sniffer may observe RESPONSE packet bytes after in-place decryption.
* Security-boundary / shared-buffer isolation concern: +2 in paranoid view. The bug mutates cloned skb data that may be shared with a sniffer, violating expected isolation between RXRPC security processing and packet capture.
* Local privileged or delegated sniffer requirement: -1 to -2. Packet capture typically requires `CAP_NET_RAW`, `CAP_NET_ADMIN`, or equivalent delegation, so the conservative score is lower.
* Network protocol security path exposure: +1. The affected code is RXRPC connection-level security verification, though the attacker receiving the disclosure is local, not remote.
* No memory corruption signal. The patch prevents in-place modification of shared skb data, but there is no UAF, OOB write, arbitrary write, or kernel LPE primitive.
* No availability signal. The reported effect is information exposure or packet corruption to an observer, not kernel crash.

3. Reachability analysis
A remote peer can cause RESPONSE packet processing, but the party that benefits from the leak is a local packet observer that can sniff cloned skbs. In typical deployments, sniffing requires elevated capabilities, but those capabilities may be delegated to monitoring tools, containers, or service accounts. The issue is not a direct remote attack against the kernel and not a normal unprivileged local trigger. Practical exploitation depends on RXRPC traffic using the affected security operation and simultaneous packet capture.

4. Severity interpretation
This is not memory corruption and not an LPE. Conservative treatment is low because the observer usually already has packet-capture privileges. Paranoid treatment is Actionable Moderate because it is a crypto/security-path shared-buffer isolation bug where decrypted packet content may cross into a packet sniffer view, which is a confidentiality boundary concern in delegated monitoring environments.

5. One-sentence report phrase
RXRPC RESPONSE verification could decrypt cloned skb data in place, allowing a local packet sniffer with capture privileges to observe partially decrypted RESPONSE contents instead of only the original encrypted packet.

6. Manual review recommendation
MANUAL CHECK RECOMMENDED. The issue is low in fully trusted sniffer environments, but it affects RXRPC security processing and may expose decrypted data across a shared skb boundary when packet capture is delegated.

======================================================================
UPSTREAM PATCH SUMMARY
======================================================================

Patch: rxrpc: Fix conn-level packet handling to unshare RESPONSE packets [ Upstream
Commit: c0428a22daf69714dc042b67ea759956b74c74e5
Upstream URL: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c0428a22daf69714dc042b67ea759956b74c74e5

Changed files:
  net/rxrpc/conn_event.c

Diff excerpt:

Not included in this email. See the upstream URL for the full patch.

Full patch:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=c0428a22daf69714dc042b67ea759956b74c74e5

======================================================================
DETAILED REPORT METHODOLOGY
======================================================================

The original Linux kernel CVE announcement for CVE-2026-46000 can be found here:
https://lore.kernel.org/linux-cve-announce/?q=CVE-2026-46000

The original CVE announcement normally does not include a security-level
estimate. In particular, it may not contain a CVSS assessment, an impact
level, or enough information to determine whether the reported bug is a
practically relevant security issue. One purpose of this parallel CVE list
is to provide that missing technical and prioritization information.

The original goal of the AL-KERNEL project was to prioritize Linux kernel
CVE analysis automatically before manual review. The system can also help
identify non-security issues that may be suitable for automatic closure.

This report was generated by AL-KERNEL, an AI-assisted Linux kernel
vulnerability analysis system developed by Alexander Larkin.

The first analysis stage combines an autonomous classifier with additional
LLM-based analysis. The autonomous classifier runs locally on a CPU and is
based on a backpropagation neural network. Together, these mechanisms
produce a technical vulnerability description, identify likely weakness
types, estimate CVSS severity, and provide input for ActionableScore.

Two CVSS estimates are retained because incomplete kernel vulnerability
information often permits more than one defensible interpretation:

  Conservative CVSS vector: AV:L/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:N
  The Best / paranoid CVSS vector: AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
  The Best / paranoid CVSS score: 3.3

The conservative vector represents a lower-impact interpretation.
The Best/paranoid vector intentionally represents a plausible upper-bound
interpretation and should not automatically be treated as demonstrated
real-world impact.

CVSS may also need to be adjusted for a particular Linux deployment,
because actual reachability, privileges, enabled kernel configuration,
hardware, namespaces, exposed device nodes, and other environmental
conditions can differ significantly between systems.

A separate ActionableScore mechanism evaluates practical remediation
urgency. Its analysis may include reachability, attack prerequisites,
subsystem exposure, memory-corruption characteristics, denial-of-service
reliability, and possible confidentiality, integrity, or
privilege-escalation impact.

  Conservative ActionableScore: 2
  Paranoid ActionableScore: 5

The final base severity is taken directly from the second tab-separated
field of the AL-KERNEL classification result. ActionableScore does not
replace or independently override that final AL-KERNEL decision, and
if ActionableScore adjusted impact level of ALKERNEL, then you would see
self-readable flags above like INCREASED_TO_HIGH_BASED_ON_ACTIONABLESCOREHIGHEREQTHAN7.

For an AL-KERNEL result of MODERATE, this report uses the following
additional presentation split:

  ActionableScore below 5   -> MODERATE REGULAR
  ActionableScore 5 or more -> MODERATE 7.0

The distinction between MODERATE REGULAR and MODERATE 7.0 makes it
possible to identify Moderate issues that should receive manual analysis
and fixes before lower-priority MODERATE REGULAR issues. In many cases,
MODERATE REGULAR fixes may wait for a later rebase or routine update.

There is one override in which MODERATE REGULAR becomes MODERATE 7.0
even when the ActionableScore is below 5. When the AL-KERNEL result
contains the KPANIC flag, a MODERATE result is always presented as
MODERATE 7.0. The KPANIC flag selected with few regexps without
usage of AI at all, so it helps to detect cases when Kernel Crash happens
and similar (to filter False-Negative results from the LLM usage).

KPANIC indicates that a reliable kernel crash, kernel panic, or similarly
serious kernel availability impact was identified by the classification
workflow.

AL-KERNEL base severity for this report: MODERATE
KPANIC detected for this report: NO
Published priority for this report (same as in Subject): MODERATE 7.0

These results are intended to support engineering triage. They are
machine-generated estimates, and cases marked for manual review should
be validated by a human security engineer before final disposition.
For more info read docs linked from here: https://kernelcve.org/
(and you can submit you own patch there to generate such a report
for non-existant CVE-id yet).

Note that in many cases this AI tool selects higher severity, than
real is (means you can expect Importants instead of Moderate 7.0 or
Moderates 7.0 instead of regular Moderates). If you see such cases,
please use reply email interface to add additional manual analyses
info to this particular CVE.
And please, please, let me know when you see Lows instead of Importants
or Important instead of Low (because particular for such cases I
need to tune this AI tool to make it better for this one and next similar).
My contact email for such notifications is alexanjelausa@gmail.com (and both
send reply to CVE record itself too and see "reply" button below for howto reply).