Answer in brief
CVE-2026-80978 records a High severity (CVSS 7.8) vulnerability in net: cap advertised IP tunnel headroom. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <bc4e05ae66c9797a0972ac44326e69c5305e0020 || >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <af0ee8f04bea22cdb331fa3509e17f81b48938ad || >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <9144f2c53a04465a6878172b523f640313c5559e || >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <6b222adeb9340306e2ff97127c76117abb9b3df8 | bc4e05ae66c9797a0972ac44326e69c5305e0020, af0ee8f04bea22cdb331fa3509e17f81b48938ad, 9144f2c53a04465a6878172b523f640313c5559e, 6b222adeb9340306e2ff97127c76117abb9b3df8 |
| Linux/Linuxgeneric | 3.11 | Not reported |
| Linux/Linuxgeneric | >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <fb889a619723032140f5d983a3a34d25a5a2bed4 || >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <b160422f8103574425e2834130e169d84c94fa1d || >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <d36e75f5669140b66515ad3a176ca6337bd80a5e || >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <84783961cb8bdb36b4f41a02ce43aafc6d52b176 || >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <bc4e05ae66c9797a0972ac44326e69c5305e0020 || >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <af0ee8f04bea22cdb331fa3509e17f81b48938ad || >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <9144f2c53a04465a6878172b523f640313c5559e || >=1a37e412a0225fcba5587f24c0dfc7636efc8b69 <6b222adeb9340306e2ff97127c76117abb9b3df8 | fb889a619723032140f5d983a3a34d25a5a2bed4, b160422f8103574425e2834130e169d84c94fa1d, d36e75f5669140b66515ad3a176ca6337bd80a5e, 84783961cb8bdb36b4f41a02ce43aafc6d52b176, bc4e05ae66c9797a0972ac44326e69c5305e0020, af0ee8f04bea22cdb331fa3509e17f81b48938ad, 9144f2c53a04465a6878172b523f640313c5559e, 6b222adeb9340306e2ff97127c76117abb9b3df8 |
Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 11, 2026
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.
Quoted source text, attributed separately from HOL analysis.