CVE-2026-63993

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Source
https://cve.org/CVERecord?id=CVE-2026-63993
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-63993.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-63993
Downstream
Published
2026-07-19T14:56:13.218Z
Modified
2026-07-22T03:31:42.359433300Z
Severity
  • 9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()
Details

In the Linux kernel, the following vulnerability has been resolved:

vxlan: do not reuse cached iphdr() value after skbtunnelcheckpmtu()

skbtunnelcheck_pmtu() can change skb->head.

Reusing oldiph afer skbtunnelcheckpmtu() can cause an UAF.

Use instead ip_hdr(skb) as done in drivers/net/bareudp.c and drivers/net/geneve.c.

Found by Sashiko.

Database specific 
{
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/63xxx/CVE-2026-63993.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
4cb47a8644cc9eb8ec81190a50e79e6530d0297f
Fixed
6b8bfce9d2f774d2c2243e0248e03efb99bba6c0
Fixed
9257f56ac47ef1976bcd056cf986a9988eeec67a
Fixed
8d435d68d71fb875876b722f4136caf74f2f48bd
Fixed
dc3bfa050f873371e745bdf478b1f5b738e5733d
Fixed
609e63312c29aad18026a1d3222e123d4b6b0feb
Fixed
5303925e360527243b46a440a04667826bbc72b7
Fixed
a493efd4336cf19122ae0e4cbb3d31b32d70deea
Fixed
7d9ef0cb271555d8cf39fefe6c981e1493b25ecf

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-63993.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
5.9.0
Fixed
5.10.259
Type
ECOSYSTEM
Events
Introduced
5.11.0
Fixed
5.15.210
Type
ECOSYSTEM
Events
Introduced
5.16.0
Fixed
6.1.176
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.143
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.12.93
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
6.18.35
Type
ECOSYSTEM
Events
Introduced
6.19.0
Fixed
7.0.12

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-63993.json"