Answer in brief
CVE-2026-98554 records a Unknown severity vulnerability in vlan: ensure sufficient headroom in vlan_dev_hard_header(). The current sources do not mark it as known exploited. The current feed maps 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.
A CVSS score is not reported in the current record. 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <55e007fc3b4d76fa4d6b4660f6904fe6ab045a1b || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5aca8e6a8ff6aeae358c1d9b65447aac416ace95 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4ba1f57313f36a3ce6f77d593548f0c511f34aa1 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ca797491f0ae4bfde9039f79f6f1ed7781c9110f || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cfba0f45553de2b803059e3d539a1e418df24da8 || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <c7ee4bea64f559ea8e03260014775b64c720cb5b || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <90d51095371d96747f45bbd8504edf6513e039ef || >=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cd5dd68267c4238795fadaf02b3575ca3f8a6500 | 55e007fc3b4d76fa4d6b4660f6904fe6ab045a1b, 5aca8e6a8ff6aeae358c1d9b65447aac416ace95, 4ba1f57313f36a3ce6f77d593548f0c511f34aa1, ca797491f0ae4bfde9039f79f6f1ed7781c9110f, cfba0f45553de2b803059e3d539a1e418df24da8, c7ee4bea64f559ea8e03260014775b64c720cb5b, 90d51095371d96747f45bbd8504edf6513e039ef, cd5dd68267c4238795fadaf02b3575ca3f8a6500 |
| Linux/Linuxgeneric | 2.6.12 | Not reported |
Published upstream
Oct 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 18, 2026
In the Linux kernel, the following vulnerability has been resolved: vlan: ensure sufficient headroom in vlan_dev_hard_header() Callers that only reserve ETH_HLEN or less (such as llc_alloc_frame()), or skbs allocated before dynamic device/headroom changes (e.g. toggling VLAN_FLAG_REORDER_HDR or bonding/team switching slaves), can reach vlan_dev_hard_header() with insufficient headroom and trigger skb_under_panic(). Use skb_cow_head() in vlan_dev_hard_header() when VLAN_FLAG_REORDER_HDR is not set to ensure sufficient headroom for the VLAN header(s) and the underlying device hard header. Use READ_ONCE() to read dev->hard_header_len and dev->needed_headroom as they can be updated concurrently under RTNL (e.g. in vlan_transfer_features()) while vlan_dev_hard_header() runs locklessly on the transmit path. Also avoid LL_RESERVED_SPACE(dev) here so that the extra HH_DATA_MOD alignment padding does not trigger unnecessary pskb_expand_head() reallocations on inner stacked VLAN devices after the outer VLAN header has been pushed.
Quoted source text, attributed separately from HOL analysis.