CVE-2026-63993
vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()
CRITICAL 9.8
At a glance
- Source
- NVD
- EPSS
- EPSS 0.51 % · percentile 44 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
Description
In 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.
Weaknesses (CWE)
- CWE-416 — Use After Free
References
- https://git.kernel.org/stable/c/6b8bfce9d2f774d2c2243e0248e03efb99bba6c0
- https://git.kernel.org/stable/c/9257f56ac47ef1976bcd056cf986a9988eeec67a
- https://git.kernel.org/stable/c/8d435d68d71fb875876b722f4136caf74f2f48bd
- https://git.kernel.org/stable/c/dc3bfa050f873371e745bdf478b1f5b738e5733d
- https://git.kernel.org/stable/c/609e63312c29aad18026a1d3222e123d4b6b0feb
- https://git.kernel.org/stable/c/5303925e360527243b46a440a04667826bbc72b7
- https://git.kernel.org/stable/c/a493efd4336cf19122ae0e4cbb3d31b32d70deea
- https://git.kernel.org/stable/c/7d9ef0cb271555d8cf39fefe6c981e1493b25ecf
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | CRITICAL 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | Linux |
| CVSS 3.1 | CRITICAL 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | NVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary) |
European references
- ENISA EUVD · EUVD-2026-45566
- GCVE · GCVE-0-2026-63993
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1373 — Multiples vulnérabilités dans les produits Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1372 — Multiples vulnérabilités dans les produits SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1335 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1286 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1255 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1252 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1229 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1203 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1162 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1066 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0954 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0926 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.9 < 5.10.259cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.11 < 5.15.210cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.16 < 6.1.176cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.2 < 6.6.143cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.93cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.18.35cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.19 < 7.0.12cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < 6b8bfce9d2f774d2c2243e0248e03efb99bba6c0 ; affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < 9257f56ac47ef1976bcd056cf986a9988eeec67a ; affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < 8d435d68d71fb875876b722f4136caf74f2f48bd ; affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < dc3bfa050f873371e745bdf478b1f5b738e5733d ; affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < 609e63312c29aad18026a1d3222e123d4b6b0feb ; affected 4cb47a8644cc9eb8ec81190a50e79e6530d0297f < 5303925e360527243b46a440a04667826bbc72b7 |
| Linux · Linux | affected 5.9 ; unaffected 0 < 5.9 ; unaffected 5.10.259 ≤ 5.10.* ; unaffected 5.15.210 ≤ 5.15.* ; unaffected 6.1.176 ≤ 6.1.* ; unaffected 6.6.143 ≤ 6.6.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |