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CVE-2026-45988
rxrpc: Fix re-decryption of RESPONSE packets
Published 2026-05-27 (5 months ago) by the Linux kernel CNA. Subsystem include/trace. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-45988 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | fixed | 6.12.86-1 | Update the kernel and reboot. Fixed in 6.12.86-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.0.4-1 | Update the kernel and reboot. Fixed in 7.0.4-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.0.4-1 | Update the kernel and reboot. Fixed in 7.0.4-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
If a RESPONSE packet gets a temporary failure during processing, it may end up in a partially decrypted state - and then get requeued for a retry. Fix this by just discarding the packet; we will send another CHALLENGE packet and thereby elicit a further response. Similarly, discard an incoming CHALLENGE packet if we get an error whilst generating a RESPONSE; the server will send another CHALLENGE.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
include/trace/events/rxrpc.h
net/rxrpc/conn_event.c
- What this is
- RXRPC SOCKETS (AF_RXRPC)MAINTAINERS section matched on include/trace/events/rxrpc.h · linux-afs@lists.infradead.org · Supported
- Kernel module
- rxrpc
Check it on the machine
grep -w CONFIG_AF_RXRPC /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w rxrpcPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookworm, trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- M
- a module where it is built at all; some flavours do not build it
- Build switch
- CONFIG_AF_RXRPC
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-05-27 (5 months ago)source
- CVSS
- 9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.46%, higher than 38.2% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- include/trace
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 2.6.22 | 6.6.140 | d61482be4aae |
| 2.6.22 | 6.12.86 | 7b8986830505 |
| 2.6.22 | 6.18.27 | 76cb9a2d2522 |
| 2.6.22 | 7.0.4 | f55b38307017 |
| 2.6.22 | 7.1 | 0422e7a4883f |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:NAttack vector, network
- rxrpc is a UDP/IP network protocol; the vulnerable CHALLENGE/RESPONSE handling processes packets received from a remote peer (a connecting client, or a malicious/spoofed AFS server) over the network.
- AC:LAttack complexity, low
- The bug is gated on a transient `-ENOMEM`/`-EAGAIN` during handshake processing, but an attacker can induce the required memory pressure by flooding the target with concurrent rxrpc handshakes, making the failing `GFP_NOFS` allocation reachable repeatably.
- PR:NPrivileges required, none
- The CHALLENGE/RESPONSE packets are processed during the security handshake before the connection is secured (`RXRPC_CONN_SERVICE_CHALLENGING`), so no authentication or credentials are needed to reach the code.
- UI:NUser interaction, none
- A server processing an incoming RESPONSE, and automated AFS clients/daemons processing a CHALLENGE, require no human interaction to trigger the fault.
- S:UScope, unchanged
- The corruption and its impact are confined to the kernel's own memory/security authority; no crossing of a VM, IOMMU, or sandbox boundary is involved.
- C:HConfidentiality impact, high
- The CHALLENGE-path refcount underflow frees the `rxrpc_connection` while still referenced; a UAF lets an attacker reallocate and read controlled freed-object contents, enabling kernel memory disclosure.
- I:HIntegrity impact, high
- The same use-after-free / refcount-underflow on the connection object enables heap grooming and write primitives over the freed structure, allowing kernel memory/control-flow corruption.
- A:HAvailability impact, high
- The double-put UAF and the re-decryption of partially-decrypted RESPONSE packets reliably oops/panic the kernel and abort connections, causing a denial of service.