--- cve: "CVE-2026-80978" severity: "HIGH" cvss: 7.8 epss: "13%" vendor: "Linux" kev: false exploited: false published: "2026-09-11 20:19:04" tags: [cve, security, high] source: tsecurity.de CVE-Dossier exported: "2026-09-18T22:35:24+02:00" --- # CVE-2026-80978 > 7.8 HIGH ## Beschreibung In the Linux kernel, the following vulnerability has been resolved: net: cap advertised IP tunnel headroom IP tunnel devices derive their advertised needed_headroom from lower output devices. A stack of user-created devices can make the derived value larger than the 16-bit skb header offsets can represent. Once IP output reserves it, skb head expansion can wrap those offsets. The runtime transmit path already caps a growing needed_headroom at 512. Apply the same cap when tunnel configuration publishes needed_headroom derived from a lower output device. Capping the advertised value is safe: IP tunnel transmit still expands the skb when a packet needs more headroom. A nonsensical stacked configuration can therefore incur an extra reallocation, but it cannot publish an unbounded reservation to upper layers. ## CVSS-Vektor ``` CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H ``` | Metrik | Wert | Bewertung | |---|---|---| | AV Angriffsvektor | Lokal | good | | AC Komplexität | Gering | bad | | PR Privilegien | Gering | warn | | UI Interaktion | Keine | bad | | S Scope | Unverändert | good | | C Vertraulichkeit | Hoch | bad | | I Integrität | Hoch | bad | | A Verfügbarkeit | Hoch | bad | ## Patch verfügbar (OSV) - Kernel ≥ 5.10.270 - Kernel ≥ 5.15.221 - Kernel ≥ 6.1.188 - Kernel ≥ 6.6.157 - Kernel ≥ 6.12.109 - Kernel ≥ 6.18.50 - Kernel ≥ 7.2.4 ## Referenzen - - - - - - - - --- _Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-80978) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_