CVE Intelligence
Medium Memory corruption

CVE-2025-21790 — vxlan: check vxlan_vnigroup_init() return value

In the Linux kernel, the following vulnerability has been resolved: vxlan: check vxlan_vnigroup_init() return value vxlan_init() must check vxlan_vnigroup_init() success otherwise a crash happens later, spotted by syzbot. Oops: general protection fault, probably for non-canonical address 0xdffffc000000002c: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000160-0x0000000000000167] CPU: 0 UID: 0 PID: 7313 Comm: syz-executor147 Not tainted 6.14.0-rc1-syzkaller-00276-g69b54314c975 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:vxlan_vnigroup_uninit+0x89/0x500 drivers/net/vxlan/vxlan_vnifilter.c:912 Code: 00 48 8b 44 24 08 4c 8b b0 98 41 00 00 49 8d 86 60 01 00 00 48 89 c2 48 89 44 24 10 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 4d 04 00 00 49 8b 86 60 01 00 00 48 ba 00 00 00 RSP: 0018:ffffc9000cc1eea8 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff8672effb RDX: 000000000000002c RSI: ffffffff8672ecb9 RDI: ffff8880461b4f18 RBP: ffff8880461b4ef4 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000020000 R13: ffff8880461b0d80 R14: 0000000000000000 R15: dffffc0000000000 FS: 00007fecfa95d6c0(0000) GS:ffff88806a600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fecfa95cfb8 CR3: 000000004472c000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> vxlan_uninit+0x1ab/0x200 drivers/net/vxlan/vxlan_core.c:2942 unregister_netdevice_many_notify+0x12d6/0x1f30 net/core/dev.c:11824 unregister_netdevice_many net/core/dev.c:11866 [inline] unregister_netdevice_queue+0x307/0x3f0 net/core/dev.c:11736 register_netdevice+0x1829/0x1eb0 net/core/dev.c:10901 __vxlan_dev_create+0x7c6/0xa30 drivers/net/vxlan/vxlan_core.c:3981 vxlan_newlink+0xd1/0x130 drivers/net/vxlan/vxlan_core.c:4407 rtnl_newlink_create net/core/rtnetlink.c:3795 [inline] __rtnl_newlink net/core/rtnetlink.c:3906 [inline]

Published Feb 27, 2025 · Updated Oct 14, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.2% (30-day exploitation probability)+2
  • Technical severity (medium)+3

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.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.23%
ahead of 13% of scored CVEs · Oct 14, 2026
Affects
Linux
Linux and 1 more
CVSS base
5.5
Medium · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

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)

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.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
  2. Apply the fixed version or the patch documented under Remediation.
  3. 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.

VendorProductVersionsStatusSource
Linux Linux ≥ f9c4bb0b245cee35ef66f75bf409c9573d934cf9 and < 79aea5e55156c87dc570e43fcd8bba01b9d6ab3f≥ f9c4bb0b245cee35ef66f75bf409c9573d934cf9 and < a303649b99b64858d62ce7428125d8e71675d2b6≥ f9c4bb0b245cee35ef66f75bf409c9573d934cf9 and < e860f847787fbbf0d8dacd638c019c7c3d4a9bd3≥ f9c4bb0b245cee35ef66f75bf409c9573d934cf9 and < 3215f5aafc49aaa993991633833854694e73b439≥ f9c4bb0b245cee35ef66f75bf409c9573d934cf9 and < 5805402dcc56241987bca674a1b4da79a249bab7version 5.18 Vulnerable CVE Program (cve.org) e CISA ADP
Linux Linux Kernel ≥ 5.18 and < 6.1.129≥ 6.2 and < 6.6.79≥ 6.7 and < 6.12.16≥ 6.13 and < 6.13.4version 6.14-rc1version 6.14-rc2 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

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

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
5.5 CVSS 3.1 Medium 1.8 3.6 nvd@nist.gov via NIST National Vulnerability Database
5.5 CVSS 3.1 Medium 1.8 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0 via NIST National Vulnerability Database
5.5 CVSS 3.1 Medium — — GitHub, Inc. via GitHub Security Advisories
5.5 CVSS 3.1 Medium — — CISA-ADP via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-476 · NULL Pointer Dereference

Other CVEs with this weakness →

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.
endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · linux/linux
    Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 14, 2026
  • Fix documented
    Oct 14, 2026 · NIST National Vulnerability Database
  • Affected products added · linux/linux kernel
    Oct 14, 2026 · NIST National Vulnerability Database
  • CVSS changed · 5.5
    Oct 14, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 14, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 14, 2026 · Alertas do Telegram
  • 2025
  • CVE published
    Feb 27, 2025 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 14, 2026 – Oct 14, 2026
  • 1× Official description updated · Oct 14, 2026 – Oct 14, 2026

References

9 on the record

Elsewhere on this site

Linux
every CVE for this vendor
Memory corruption
same class
CWE-476
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-99999 ipv4: validate checksum_start before completing checksum 7h
  • CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 7h
  • CVE-2026-98429 RDMA/efa: Keep EQ resources alive while IRQ is registered 1d
  • CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
  • CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
  • CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 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 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-2025-21790 is "vxlan: check vxlan_vnigroup_init() return value", rated Medium. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.23% estimates the probability of exploitation in 30 days; neither replaces your asset context. 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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