NVD / CVE Program· CNA Linux

CVE-2025-21760: ndisc: extend RCU protection in ndisc_send_skb()

Noroxi assessment

Priority: Plan (action score 43/100)

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: 37.9% (FIRST EPSS); higher than 98.5% 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. Special conditions such as timing or configuration are required.
Fixed version: Linux Linux 04e05112f10354ffc3bb6cc796d553bab161594c, 10a1f3fece2f0d23a3a618b72b2b4e6f408ef7d1, 4d576202b90b1b95a7c428a80b536f91b8201bcc; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.82.1-1; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.82.1-1.

Add it to your regular patch cycle. Upgrade to Linux Linux 04e05112f10354ffc3bb6cc796d553bab161594c, 10a1f3fece2f0d23a3a618b72b2b4e6f408ef7d1, 4d576202b90b1b95a7c428a80b536f91b8201bcc; azl3 kernel 6.6.78.1-3 on Azure Linux 3.0 6.6.82.1-1; azl3 kernel 6.6.82.1-1 on Azure Linux 3.0 6.6.82.1-1 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: ndisc: extend RCU protection in ndisc_send_skb() ndisc_send_skb() can be called without RTNL or RCU held. Acquire rcu_read_lock() earlier, so that we can use dev_net_rcu() and avoid a potential UAF.

HighCVSS 8.1 · v3.1—No exploit Fix available

Published: Feb 27, 2025
Updated: Oct 15, 2026
EPSS: 37.9% · 98th percentile
CWE: CWE-416

Report tools

JSON

Action score

Plan

Add it to your regular patch cycle.

CVSS: 32 / 40 · 8.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 11 / 30 · 37.9%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 8.1; 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

If any of these changes, we'll tell you in the daily email digest.

Running WordPress? Scan your site free with WP Lens

Is your version affected? Check it

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.

We use this product, ask for help

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 kernel2.6.26 and later · before 5.4.291
linux linux kernel5.5 and later · before 5.10.235
linux linux kernel5.11 and later · before 5.15.179
linux linux kernel5.16 and later · before 6.1.129
linux linux kernel6.2 and later · before 6.6.79
linux linux kernel6.7 and later · before 6.12.16
linux linux kernel6.13 and later · before 6.13.4
linux linux kernel6.14

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
- 2.6.26affected
- 1762f7e88eb34f653b4a915be99a102e347dd45e and later · before 10a1f3fece2f0d23a3a618b72b2b4e6f408ef7d1affected · git
- 1762f7e88eb34f653b4a915be99a102e347dd45e and later · before 4d576202b90b1b95a7c428a80b536f91b8201bccaffected · git
- 1762f7e88eb34f653b4a915be99a102e347dd45e and later · before e24d225e4cb8cf108bde00b76594499b98f0a74daffected · git
- 1762f7e88eb34f653b4a915be99a102e347dd45e and later · before a9319d800b5701e7f5e3fa71a5b7c4831fc20d6daffected · git
- 1762f7e88eb34f653b4a915be99a102e347dd45e and later · before ae38982f521621c216fc2f5182cd091f4734641daffected · git
- 1762f7e88eb34f653b4a915be99a102e347dd45e and later · before 789230e5a8c1097301afc802e242c79bc8835c67affected · git
- 1762f7e88eb34f653b4a915be99a102e347dd45e and later · before 04e05112f10354ffc3bb6cc796d553bab161594caffected · git
- 1762f7e88eb34f653b4a915be99a102e347dd45e and later · before ed6ae1f325d3c43966ec1b62ac1459e2b8e45640affected · git
- before 2.6.26not 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	before 6.1.129-1	6.1.129-1
Debian:13	linux	before 6.12.16-1	6.12.16-1
SUSE:Linux Enterprise Micro 5.2	kernel-default	before 5.3.18-150300.59.235.1	5.3.18-150300.59.235.1
SUSE:Linux Enterprise Micro 5.2	kernel-default-base	before 5.3.18-150300.59.235.1.150300.18.140.1	5.3.18-150300.59.235.1.150300.18.140.1
SUSE:Linux Enterprise Micro 5.2	kernel-rt	before 5.3.18-150300.235.1	5.3.18-150300.235.1
SUSE:Linux Enterprise Micro 5.2	kernel-source-rt	before 5.3.18-150300.235.1	5.3.18-150300.235.1
SUSE:Linux Enterprise Micro 5.3	kernel-rt	before 5.14.21-150400.15.145.1	5.14.21-150400.15.145.1
SUSE:Linux Enterprise Micro 5.3	kernel-source-rt	before 5.14.21-150400.15.145.1	5.14.21-150400.15.145.1

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-2025-21758Feb 27, 2025 · ipv6: mcast: add RCU protection to mld_newpack()
27Monitor
← EarlierCVE-2025-21759Feb 27, 2025 · ipv6: mcast: extend RCU protection in igmp6_send()
33Monitor
Later →CVE-2025-21761Feb 27, 2025 · openvswitch: use RCU protection in ovs_vport_cmd_fill_info()
31Monitor

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	04e05112f10354ffc3bb6cc796d553bab161594c	Vendor (CNA)
Linux Linux	10a1f3fece2f0d23a3a618b72b2b4e6f408ef7d1	Vendor (CNA)
Linux Linux	4d576202b90b1b95a7c428a80b536f91b8201bcc	Vendor (CNA)
Linux Linux	789230e5a8c1097301afc802e242c79bc8835c67	Vendor (CNA)
Linux Linux	a9319d800b5701e7f5e3fa71a5b7c4831fc20d6d	Vendor (CNA)
Linux Linux	ae38982f521621c216fc2f5182cd091f4734641d	Vendor (CNA)
Linux Linux	e24d225e4cb8cf108bde00b76594499b98f0a74d	Vendor (CNA)
Linux Linux	ed6ae1f325d3c43966ec1b62ac1459e2b8e45640	Vendor (CNA)
azl3 kernel 6.6.78.1-3 on Azure Linux 3.0	6.6.82.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
azl3 kernel 6.6.82.1-1 on Azure Linux 3.0	6.6.82.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
cbl2 kernel 5.15.176.3-3 on CBL Mariner 2.0	5.15.180.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
cbl2 kernel 5.15.176.3-3 on CBL-Mariner 2.0	5.15.180.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
cbl2 kernel 5.15.180.1-1 on CBL Mariner 2.0	5.15.180.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.129-1 · Debian:12	Package registry (OSV)
suse:kernel-default	5.3.18-150300.59.235.1 · SUSE:Linux Enterprise Micro 5.2	Package registry (OSV)
suse:kernel-default-base	5.3.18-150300.59.235.1.150300.18.140.1 · SUSE:Linux Enterprise Micro 5.2	Package registry (OSV)
suse:kernel-rt	5.3.18-150300.235.1 · SUSE:Linux Enterprise Micro 5.2	Package registry (OSV)
suse:kernel-source-rt	5.3.18-150300.235.1 · SUSE:Linux Enterprise Micro 5.2	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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

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.
Special conditions such as timing or configuration are required.

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: Network
Attack complexity: High
Privileges required: None
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:N/AC:H/PR:N/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, 10:09 PM UTC

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

References

git.kernel.org/stable/c/04e05112f10354ffc3bb6cc796d553bab161594c

Show all references (13 more)

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

All records