CVE-2026-64188 — net: qualcomm: rmnet: fix endpoint use-after-free in rmnet_dellink()
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
version 4.14≥ ceed73a2cf4aff2921802aa3d21d45280677547d and < d00c953a8f69921f484b629801766da68f27f658≥ ceed73a2cf4aff2921802aa3d21d45280677547d and < f193e38cb257d033060b63f1cfd94af076b3a2ab≥ ceed73a2cf4aff2921802aa3d21d45280677547d and < 8b17adf6d4fb6bf61fa4c3f58366a7c082799a71≥ ceed73a2cf4aff2921802aa3d21d45280677547d and < 41e06fcc5df0774d212e70c5b503fc769492bce3≥ ceed73a2cf4aff2921802aa3d21d45280677547d and < 1078ae8175777e80c9637996fb4a46c55f0ce576≥ ceed73a2cf4aff2921802aa3d21d45280677547d and < 310b93246bfec7d4452507e0c15477377ed9f025≥ ceed73a2cf4aff2921802aa3d21d45280677547d and < 9918698cf3aee4032e12bb42fd5a951dc465339b and 1 more≥ ceed73a2cf4aff2921802aa3d21d45280677547d and < c4e676c3505c5058922dc1a6f1ded795f6758135 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
version 7.1-rc4≥ 4.14 and < 5.10.260version 7.1-rc3version 7.1-rc2version 7.1-rc1≥ 6.19 and < 7.0.14≥ 6.13 and < 6.18.37≥ 6.7 and < 6.12.95 and 3 more≥ 6.2 and < 6.6.144≥ 5.16 and < 6.1.177≥ 5.11 and < 5.15.211 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- CVSS changed · 7.8
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
8 on the record
- git.kernel.org/stable/c/8b17adf6d4fb6bf61fa4c3f58366a7c082799a71
- git.kernel.org/stable/c/9918698cf3aee4032e12bb42fd5a951dc465339b
- git.kernel.org/stable/c/1078ae8175777e80c9637996fb4a46c55f0ce576
- git.kernel.org/stable/c/41e06fcc5df0774d212e70c5b503fc769492bce3
- git.kernel.org/stable/c/d00c953a8f69921f484b629801766da68f27f658
- git.kernel.org/stable/c/f193e38cb257d033060b63f1cfd94af076b3a2ab
- git.kernel.org/stable/c/c4e676c3505c5058922dc1a6f1ded795f6758135
- git.kernel.org/stable/c/310b93246bfec7d4452507e0c15477377ed9f025
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 9h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 9h
- Unknown CVE-2026-98431 RDMA/uverbs: Fix mmap_lock/disassociation_lock circular dependency 1d
- Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 1d
- Unknown CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d
- Unknown CVE-2026-98428 ALSA: usb: 6fire: Avoid embedded URBs 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No CISA SSVC assessment.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-64188 is "net: qualcomm: rmnet: fix endpoint use-after-free in rmnet_dellink()", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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