NVD / CVE Program· CNA Linux

CVE-2026-64188: net: qualcomm: rmnet: fix endpoint use-after-free in rmnet_dellink()

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: 0.11% (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 1078ae8175777e80c9637996fb4a46c55f0ce576, 310b93246bfec7d4452507e0c15477377ed9f025, 41e06fcc5df0774d212e70c5b503fc769492bce3; azl3 kernel 6.6.143.1-1 on Azure Linux 3.0 6.6.150.1-1.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 1078ae8175777e80c9637996fb4a46c55f0ce576, 310b93246bfec7d4452507e0c15477377ed9f025, 41e06fcc5df0774d212e70c5b503fc769492bce3; azl3 kernel 6.6.143.1-1 on Azure Linux 3.0 6.6.150.1-1 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: net: qualcomm: rmnet: fix endpoint use-after-free in rmnet_dellink() rmnet_dellink() removes the endpoint from the hash table with hlist_del_init_rcu() and then immediately frees it with kfree(). However, RCU readers on the receive path (rmnet_rx_handler -> __rmnet_map_ingress_handler) may still hold a reference to the endpoint and dereference ep->egress_dev after the memory has been freed. The endpoint is a kmalloc-32 object, and the stale read at offset 8 corresponds to the egress_dev pointer. BUG: unable to handle page fault for address: ffffffffde942eef Oops: 0002 [#1] SMP NOPTI CPU: 1 UID: 0 PID: 137 Comm: poc_write Not tainted 7.0.0+ #4 PREEMPTLAZY RIP: 0010:rmnet_vnd_rx_fixup (rmnet_vnd.c:27) Call Trace: <TASK> __rmnet_map_ingress_handler (rmnet_handlers.c:48 rmnet_handlers.c:101) rmnet_rx_handler (rmnet_handlers.c:129 rmnet_handlers.c:235) __netif_receive_skb_core.constprop.0 (net/core/dev.c:6096) __netif_receive_skb_one_core (net/core/dev.c:6208) netif_receive_skb (net/core/dev.c:6467) tun_get_user (drivers/net/tun.c:1955) tun_chr_write_iter (drivers/net/tun.c:2003) vfs_write (fs/read_write.c:688) ksys_write (fs/read_write.c:740) </TASK> Add an rcu_head field to struct rmnet_endpoint and replace kfree() with kfree_rcu() so the endpoint memory remains valid through the RCU grace period. Also remove the rmnet_vnd_dellink() call and inline only the nr_rmnet_devs decrement, since rmnet_vnd_dellink() would set ep->egress_dev to NULL during the grace period, creating a data race with lockless readers.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

Published: Jul 20, 2026
Updated: Aug 11, 2026
EPSS: 0.1% · 1th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.1%

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

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 kernel4.14 and later · before 5.10.260
linux linux kernel5.11 and later · before 5.15.211
linux linux kernel5.16 and later · before 6.1.177
linux linux kernel6.2 and later · before 6.6.144
linux linux kernel6.7 and later · before 6.12.95
linux linux kernel6.13 and later · before 6.18.37
linux linux kernel6.19 and later · before 7.0.14
linux linux kernel7.1

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
- 4.14affected
- ceed73a2cf4aff2921802aa3d21d45280677547d and later · before c4e676c3505c5058922dc1a6f1ded795f6758135affected · git
- ceed73a2cf4aff2921802aa3d21d45280677547d and later · before 9918698cf3aee4032e12bb42fd5a951dc465339baffected · git
- ceed73a2cf4aff2921802aa3d21d45280677547d and later · before 310b93246bfec7d4452507e0c15477377ed9f025affected · git
- ceed73a2cf4aff2921802aa3d21d45280677547d and later · before 1078ae8175777e80c9637996fb4a46c55f0ce576affected · git
- ceed73a2cf4aff2921802aa3d21d45280677547d and later · before 41e06fcc5df0774d212e70c5b503fc769492bce3affected · git
- ceed73a2cf4aff2921802aa3d21d45280677547d and later · before 8b17adf6d4fb6bf61fa4c3f58366a7c082799a71affected · git
- ceed73a2cf4aff2921802aa3d21d45280677547d and later · before f193e38cb257d033060b63f1cfd94af076b3a2abaffected · git
- ceed73a2cf4aff2921802aa3d21d45280677547d and later · before d00c953a8f69921f484b629801766da68f27f658affected · git
- before 4.14not 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 6.1.177-1	6.1.177-1
Debian:13	linux	before 6.12.95-1	6.12.95-1
Debian:14	linux	before 7.0.14-1	7.0.14-1

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-2026-64185Jul 19, 2026 · sysfs: don't remove existing directory on update failure
22Monitor
← EarlierCVE-2026-64186Jul 19, 2026 · iommu/amd: Remove latent out-of-bounds access in IOMMU debugfs
28Monitor
Later →CVE-2026-64207Jul 20, 2026 · net/sched: dualpi2: fix GSO backlog accounting
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	1078ae8175777e80c9637996fb4a46c55f0ce576	Vendor (CNA)
Linux Linux	310b93246bfec7d4452507e0c15477377ed9f025	Vendor (CNA)
Linux Linux	41e06fcc5df0774d212e70c5b503fc769492bce3	Vendor (CNA)
Linux Linux	8b17adf6d4fb6bf61fa4c3f58366a7c082799a71	Vendor (CNA)
Linux Linux	9918698cf3aee4032e12bb42fd5a951dc465339b	Vendor (CNA)
Linux Linux	c4e676c3505c5058922dc1a6f1ded795f6758135	Vendor (CNA)
Linux Linux	d00c953a8f69921f484b629801766da68f27f658	Vendor (CNA)
Linux Linux	f193e38cb257d033060b63f1cfd94af076b3a2ab	Vendor (CNA)
azl3 kernel 6.6.143.1-1 on Azure Linux 3.0	6.6.150.1-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.177-1 · Debian:12	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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-26-0590 · Jul 21, 2026(Linux Kernel Güvenlik Bildirimi)

All national notices →

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, 10:11 PM UTC

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

References

git.kernel.org/stable/c/1078ae8175777e80c9637996fb4a46c55f0ce576

Show all references (7 more)

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

All records