vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-63993
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-19 16:17:38 UTC
Updated2026-07-20 15:17:00 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu() skb_tunnel_check_pmtu() can change skb->head. Reusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF. Use instead ip_hdr(skb) as done in drivers/net/bareudp.c and drivers/net/geneve.c. Found by Sashiko.

Risk And Classification

Primary CVSS: v3.1 9.8 CRITICAL from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.001760000 probability, percentile 0.073850000 (date 2026-07-20)

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f 6b8bfce9d2f774d2c2243e0248e03efb99bba6c0 git Not specified
CNA Linux Linux affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f 9257f56ac47ef1976bcd056cf986a9988eeec67a git Not specified
CNA Linux Linux affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f 8d435d68d71fb875876b722f4136caf74f2f48bd git Not specified
CNA Linux Linux affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f dc3bfa050f873371e745bdf478b1f5b738e5733d git Not specified
CNA Linux Linux affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f 609e63312c29aad18026a1d3222e123d4b6b0feb git Not specified
CNA Linux Linux affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f 5303925e360527243b46a440a04667826bbc72b7 git Not specified
CNA Linux Linux affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f a493efd4336cf19122ae0e4cbb3d31b32d70deea git Not specified
CNA Linux Linux affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f 7d9ef0cb271555d8cf39fefe6c981e1493b25ecf git Not specified
CNA Linux Linux affected 5.9 Not specified
CNA Linux Linux unaffected 5.9 semver Not specified
CNA Linux Linux unaffected 5.10.259 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.210 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.176 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.143 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.93 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.35 6.18.* semver Not specified
CNA Linux Linux unaffected 7.0.12 7.0.* semver Not specified
CNA Linux Linux unaffected 7.1 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/a493efd4336cf19122ae0e4cbb3d31b32d70deea 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/609e63312c29aad18026a1d3222e123d4b6b0feb 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/5303925e360527243b46a440a04667826bbc72b7 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/dc3bfa050f873371e745bdf478b1f5b738e5733d 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/9257f56ac47ef1976bcd056cf986a9988eeec67a 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/7d9ef0cb271555d8cf39fefe6c981e1493b25ecf 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/8d435d68d71fb875876b722f4136caf74f2f48bd 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/6b8bfce9d2f774d2c2243e0248e03efb99bba6c0 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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