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NVD / CVE Program· CNA Linux

CVE-2026-31420: bridge: mrp: reject zero test interval to avoid OOM panic

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.09% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 1ec86b4b9e28170a2565cf36f0e6e2b96b55134d, 2120bd8546cd6a63c558d135773aa8f41c8259fc, 610073ffb77ffd2b5eca182d2ac264de4834a175.

Low priority for now. Upgrade to Linux Linux 1ec86b4b9e28170a2565cf36f0e6e2b96b55134d, 2120bd8546cd6a63c558d135773aa8f41c8259fc, 610073ffb77ffd2b5eca182d2ac264de4834a175 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: bridge: mrp: reject zero test interval to avoid OOM panic br_mrp_start_test() and br_mrp_start_in_test() accept the user-supplied interval value from netlink without validation. When interval is 0, usecs_to_jiffies(0) yields 0, causing the delayed work (br_mrp_test_work_expired / br_mrp_in_test_work_expired) to reschedule itself with zero delay. This creates a tight loop on system_percpu_wq that allocates and transmits MRP test frames at maximum rate, exhausting all system memory and causing a kernel panic via OOM deadlock. The same zero-interval issue applies to br_mrp_start_in_test_parse() for interconnect test frames. Use NLA_POLICY_MIN(NLA_U32, 1) in the nla_policy tables for both IFLA_BRIDGE_MRP_START_TEST_INTERVAL and IFLA_BRIDGE_MRP_START_IN_TEST_INTERVAL, so zero is rejected at the netlink attribute parsing layer before the value ever reaches the workqueue scheduling code. This is consistent with how other bridge subsystems (br_fdb, br_mst) enforce range constraints on netlink attributes.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Apr 13, 2026
Updated
Sep 14, 2026
EPSS
0.0% · 0th percentile

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.0%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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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 kernel5.8 and later · before 6.19.12
  • 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

    • 5.8affected
    • 20f6a05ef63594feb0c6dfbd629da0448b43124d and later · before 610073ffb77ffd2b5eca182d2ac264de4834a175affected · git
    • 20f6a05ef63594feb0c6dfbd629da0448b43124d and later · before ec8850be9b2b3beac1c7967d95f169dd2785979daffected · git
    • 20f6a05ef63594feb0c6dfbd629da0448b43124d and later · before 1ec86b4b9e28170a2565cf36f0e6e2b96b55134daffected · git
    • 20f6a05ef63594feb0c6dfbd629da0448b43124d and later · before 2120bd8546cd6a63c558d135773aa8f41c8259fcaffected · git
    • 20f6a05ef63594feb0c6dfbd629da0448b43124d and later · before 630a15a31c2034b5b697f4aabc769b9d80d82446affected · git
    • 20f6a05ef63594feb0c6dfbd629da0448b43124d and later · before e8ec80430bfa520e7352155d6ac632e527cba7aaaffected · git
    • 20f6a05ef63594feb0c6dfbd629da0448b43124d and later · before c9bc352f716d1bebfe43354bce539ec2d0223b30affected · git
    • 20f6a05ef63594feb0c6dfbd629da0448b43124d and later · before fa6e24963342de4370e3a3c9af41e38277b74cf3affected · git
    • before 5.8not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.190-16.1.190-1
Debian:13linuxbefore 6.12.94-16.12.94-1
Debian:14linuxbefore 6.19.12-16.19.12-1

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-2026-31412Apr 10, 2026 · usb: gadget: f_mass_storage: Fix potential integer overflow in check_command_size_in_blocks()
    22Monitor
  • ← EarlierCVE-2026-31413Apr 12, 2026 · bpf: Fix unsound scalar forking in maybe_fork_scalars() for BPF_OR
    31Monitor
  • Later →CVE-2026-31425Apr 13, 2026 · rds: ib: reject FRMR registration before IB connection is established
    22Monitor

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 Linux1ec86b4b9e28170a2565cf36f0e6e2b96b55134dVendor (CNA)
Linux Linux2120bd8546cd6a63c558d135773aa8f41c8259fcVendor (CNA)
Linux Linux610073ffb77ffd2b5eca182d2ac264de4834a175Vendor (CNA)
Linux Linux630a15a31c2034b5b697f4aabc769b9d80d82446Vendor (CNA)
Linux Linuxc9bc352f716d1bebfe43354bce539ec2d0223b30Vendor (CNA)
Linux Linuxe8ec80430bfa520e7352155d6ac632e527cba7aaVendor (CNA)
Linux Linuxec8850be9b2b3beac1c7967d95f169dd2785979dVendor (CNA)
Linux Linuxfa6e24963342de4370e3a3c9af41e38277b74cf3Vendor (CNA)
debian:linux6.1.190-1 · Debian:12Package registry (OSV)
debian:linux6.12.94-1 · Debian:13Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

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.

No dated events beyond publication.

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

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • 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
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-667 · Improper Locking

CVSS vector

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

nvd-primary

Attack context

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

Change log

  1. Fix✗ → ✓

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

References

Show all references (7 more)

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

All records