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NVD / CVE Program· CNA Linux

CVE-2026-31635: rxrpc: fix oversized RESPONSE authenticator length check

HighCVSS 7.5 · v3.1—Proof of concept Fix available

Noroxi assessment

Priority: Monitor (action score 30/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 1.1% (FIRST EPSS); higher than 66.7% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux a2567217ade970ecc458144b6be469bc015b23e5, beee051f259acd286fed64c32c2b31e6f5097eb5, e2f1a80d8b1ed6a5ae585a399c2b46500bdcc305.

Low priority for now. Upgrade to Linux Linux a2567217ade970ecc458144b6be469bc015b23e5, beee051f259acd286fed64c32c2b31e6f5097eb5, e2f1a80d8b1ed6a5ae585a399c2b46500bdcc305 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: rxrpc: fix oversized RESPONSE authenticator length check rxgk_verify_response() decodes auth_len from the packet and is supposed to verify that it fits in the remaining bytes. The existing check is inverted, so oversized RESPONSE authenticators are accepted and passed to rxgk_decrypt_skb(), which can later reach skb_to_sgvec() with an impossible length and hit BUG_ON(len). Decoded from the original latest-net reproduction logs with scripts/decode_stacktrace.sh: RIP: __skb_to_sgvec() [net/core/skbuff.c:5285 (discriminator 1)] Call Trace: skb_to_sgvec() [net/core/skbuff.c:5305] rxgk_decrypt_skb() [net/rxrpc/rxgk_common.h:81] rxgk_verify_response() [net/rxrpc/rxgk.c:1268] rxrpc_process_connection() [net/rxrpc/conn_event.c:266 net/rxrpc/conn_event.c:364 net/rxrpc/conn_event.c:386] process_one_work() [kernel/workqueue.c:3281] worker_thread() [kernel/workqueue.c:3353 kernel/workqueue.c:3440] kthread() [kernel/kthread.c:436] ret_from_fork() [arch/x86/kernel/process.c:164] Reject authenticator lengths that exceed the remaining packet payload.

Published
Apr 24, 2026
Updated
Nov 11, 2026
EPSS
1.1% · 66th percentile

Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 1.1%

CISA SSVC decision

Exploitation
proof of concept
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
7.5
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • Proof of concept exists, no weaponized module
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.16.1 and later · before 6.18.23
  • linux linux kernel6.19 and later · before 6.19.13
  • linux linux kernel6.16
  • linux linux kernel7.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 6.16affected
    • 9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a and later · before beee051f259acd286fed64c32c2b31e6f5097eb5affected · git
    • 9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a and later · before e2f1a80d8b1ed6a5ae585a399c2b46500bdcc305affected · git
    • 9d1d2b59341f58126a69b51f9f5f8ccb9f12e54a and later · before a2567217ade970ecc458144b6be469bc015b23e5affected · git
    • before 6.16not affected · semver
    • 6.18.23 and later · up to and including 6.18.*not affected · semver
    • 6.19.13 and later · up to and including 6.19.*not affected · semver
    • 7.0 and laternot affected · original_commit_for_fix

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
AlmaLinux:10kernelbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64kbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-corebefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-debugbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-debug-corebefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-debug-develbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-debug-devel-matchedbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-debug-modulesbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-corebefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-debug-modules-extrabefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-develbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-devel-matchedbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-modulesbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-modules-corebefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-64k-modules-extrabefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-corebefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-cross-headersbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-debugbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-debug-corebefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-debug-develbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-debug-devel-matchedbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-debug-modulesbefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2
AlmaLinux:10kernel-debug-modules-corebefore 6.12.0-211.40.1.el10_26.12.0-211.40.1.el10_2

+96

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-31633Apr 24, 2026 · rxrpc: Fix integer overflow in rxgk_verify_response()
    39Monitor
  • ← EarlierCVE-2026-31634Apr 24, 2026 · rxrpc: fix reference count leak in rxrpc_server_keyring()
    22Monitor
  • Later →CVE-2026-31636Apr 24, 2026 · rxrpc: fix RESPONSE authenticator parser OOB read
    36Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linuxa2567217ade970ecc458144b6be469bc015b23e5Vendor (CNA)
Linux Linuxbeee051f259acd286fed64c32c2b31e6f5097eb5Vendor (CNA)
Linux Linuxe2f1a80d8b1ed6a5ae585a399c2b46500bdcc305Vendor (CNA)
almalinux:kernel6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-core6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-core6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-devel-matched6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-core6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-debug-modules-extra6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
almalinux:kernel-64k-devel-matched6.12.0-211.40.1.el10_2 · AlmaLinux:10Package registry (OSV)
debian:linux6.19.13-1 · Debian:14Package registry (OSV)
red hat:kernel-64k-debug-debuginfo0:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel0:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debug-devel-matched0:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-debuginfo0:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel0:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-64k-devel-matched0:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-debuginfo0:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel0:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debug-devel-matched0:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo0:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo-common-aarch640:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)
red hat:kernel-debuginfo-common-ppc64le0:6.12.0-211.40.1.el10_2 · Red Hat:enterprise_linux:10.2Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×3

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:82026-05-19
Proof-of-concept repository on GitHubstars:32026-05-21
Proof-of-concept repository on GitHubstars:02026-05-21

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+24 d
  3. TodayNov 12, 2026+202 d

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-130 · Improper Handling of Length Parameter Inconsistency

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records