NVD / CVE Program· CNA Linux

CVE-2025-21714: RDMA/mlx5: Fix implicit ODP use after free

Noroxi assessment

Priority: Monitor (action score 31/100)

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: 0.24% (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 032f3f799fdb807a21467b7dc7d620395a735e2b, 7cc8f681f6d4ae4478ae0f60485fc768f2b450da, a306dfff6b76aafa264ad33874a8992a8d5858b7; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes.

Low priority for now. Upgrade to Linux Linux 032f3f799fdb807a21467b7dc7d620395a735e2b, 7cc8f681f6d4ae4478ae0f60485fc768f2b450da, a306dfff6b76aafa264ad33874a8992a8d5858b7; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 Release Notes; azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 Release Notes 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: RDMA/mlx5: Fix implicit ODP use after free Prevent double queueing of implicit ODP mr destroy work by using __xa_cmpxchg() to make sure this is the only time we are destroying this specific mr. Without this change, we could try to invalidate this mr twice, which in turn could result in queuing a MR work destroy twice, and eventually the second work could execute after the MR was freed due to the first work, causing a user after free and trace below. refcount_t: underflow; use-after-free. WARNING: CPU: 2 PID: 12178 at lib/refcount.c:28 refcount_warn_saturate+0x12b/0x130 Modules linked in: bonding ib_ipoib vfio_pci ip_gre geneve nf_tables ip6_gre gre ip6_tunnel tunnel6 ipip tunnel4 ib_umad rdma_ucm mlx5_vfio_pci vfio_pci_core vfio_iommu_type1 mlx5_ib vfio ib_uverbs mlx5_core iptable_raw openvswitch nsh rpcrdma ib_iser libiscsi scsi_transport_iscsi rdma_cm iw_cm ib_cm ib_core xt_conntrack xt_MASQUERADE nf_conntrack_netlink nfnetlink xt_addrtype iptable_nat nf_nat br_netfilter rpcsec_gss_krb5 auth_rpcgss oid_registry overlay zram zsmalloc fuse [last unloaded: ib_uverbs] CPU: 2 PID: 12178 Comm: kworker/u20:5 Not tainted 6.5.0-rc1_net_next_mlx5_58c644e #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Workqueue: events_unbound free_implicit_child_mr_work [mlx5_ib] RIP: 0010:refcount_warn_saturate+0x12b/0x130 Code: 48 c7 c7 38 95 2a 82 c6 05 bc c6 fe 00 01 e8 0c 66 aa ff 0f 0b 5b c3 48 c7 c7 e0 94 2a 82 c6 05 a7 c6 fe 00 01 e8 f5 65 aa ff <0f> 0b 5b c3 90 8b 07 3d 00 00 00 c0 74 12 83 f8 01 74 13 8d 50 ff RSP: 0018:ffff8881008e3e40 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000027 RDX: ffff88852c91b5c8 RSI: 0000000000000001 RDI: ffff88852c91b5c0 RBP: ffff8881dacd4e00 R08: 00000000ffffffff R09: 0000000000000019 R10: 000000000000072e R11: 0000000063666572 R12: ffff88812bfd9e00 R13: ffff8881c792d200 R14: ffff88810011c005 R15: ffff8881002099c0 FS: 0000000000000000(0000) GS:ffff88852c900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5694b5e000 CR3: 00000001153f6003 CR4: 0000000000370ea0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> ? refcount_warn_saturate+0x12b/0x130 free_implicit_child_mr_work+0x180/0x1b0 [mlx5_ib] process_one_work+0x1cc/0x3c0 worker_thread+0x218/0x3c0 kthread+0xc6/0xf0 ret_from_fork+0x1f/0x30 </TASK>

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2025-03896

Published: Feb 27, 2025
Updated: Oct 30, 2026
EPSS: 0.2% · 15th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.2%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 7.8; 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.

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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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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

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

linux linux kernel5.5 and later · before 6.12.13
linux linux kernel6.13 and later · before 6.13.2

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
- 5.5affected
- 5256edcb98a14b11409a2d323f56a70a8b366363 and later · before 032f3f799fdb807a21467b7dc7d620395a735e2baffected · git
- 5256edcb98a14b11409a2d323f56a70a8b366363 and later · before a306dfff6b76aafa264ad33874a8992a8d5858b7affected · git
- 5256edcb98a14b11409a2d323f56a70a8b366363 and later · before 7cc8f681f6d4ae4478ae0f60485fc768f2b450daaffected · git
- 5256edcb98a14b11409a2d323f56a70a8b366363 and later · before edfb65dbb9ffd3102f3ff4dd21316158e56f1976affected · git
- 5256edcb98a14b11409a2d323f56a70a8b366363 and later · before d3d930411ce390e532470194296658a960887773affected · git
- before 5.5not affected · semver
- 6.1.191 and later · up to and including 6.1.*not affected · semver
- 6.6.160 and later · up to and including 6.6.*not affected · semver
- 6.12.13 and later · up to and including 6.12.*not affected · semver

Package-level exposure

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

Ecosystem	Package	Affected range	Fix
Debian:12	linux	from 0	—
Debian:13	linux	before 6.12.13-1	6.12.13-1

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-2025-21709Feb 27, 2025 · kernel: be more careful about dup_mmap() failures and uprobe registering
22Monitor
← EarlierCVE-2025-21712Feb 27, 2025 · md/md-bitmap: Synchronize bitmap_get_stats() with bitmap lifetime
22Monitor
Later →CVE-2025-21716Feb 27, 2025 · vxlan: Fix uninit-value in vxlan_vnifilter_dump()
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 / package	Fixed version	Source
Linux Linux	032f3f799fdb807a21467b7dc7d620395a735e2b	Vendor (CNA)
Linux Linux	7cc8f681f6d4ae4478ae0f60485fc768f2b450da	Vendor (CNA)
Linux Linux	a306dfff6b76aafa264ad33874a8992a8d5858b7	Vendor (CNA)
Linux Linux	d3d930411ce390e532470194296658a960887773	Vendor (CNA)
Linux Linux	edfb65dbb9ffd3102f3ff4dd21316158e56f1976	Vendor (CNA)
azl3 kernel 6.6.152.1-1 on Azure Linux 3.0	Release Notes	Microsoft (MSRC)
azl3 kernel 6.6.157.1-1 on Azure Linux 3.0	Release Notes	Microsoft (MSRC)
azl3 kernel 6.6.159.1-1 on Azure Linux 3.0	Release Notes	Microsoft (MSRC)
azl3 kernel 6.6.161.1-1 on Azure Linux 3.0	Release Notes	Microsoft (MSRC)
cbl2 kernel 5.15.202.1-1 on CBL-Mariner 2.0	Release Notes	Microsoft (MSRC)
debian:linux	6.12.13-1 · Debian:13	Package 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: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

Attack context

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

Fix✗ → ✓Sep 28, 2026, 10:10 PM UTC

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

References

git.kernel.org/stable/c/032f3f799fdb807a21467b7dc7d620395a735e2b

Show all references (4 more)

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

All records