GHSA-FQ9X-8G2W-4P5R
Vulnerability from github – Published: 2026-06-25 09:31 – Updated: 2026-10-15 03:36In the Linux kernel, the following vulnerability has been resolved:
6lowpan: fix off-by-one in multicast context address compression
The second memcpy in lowpan_iphc_mcast_ctx_addr_compress() uses &data[1] as destination and &ipaddr->s6_addr[11] as source, but both should be offset by one: &data[2] and &ipaddr->s6_addr[12] respectively.
This off-by-one has two consequences: 1. data[1] is overwritten with s6_addr[11], corrupting the RIID field in the compressed multicast address 2. data[5] is never written, so uninitialized kernel stack memory is transmitted over the network via lowpan_push_hc_data(), leaking kernel stack contents
The correct inline data layout must match what the decompression function lowpan_uncompress_multicast_ctx_daddr() expects: data[0..1] = s6_addr[1..2] (flags/scope + RIID) data[2..5] = s6_addr[12..15] (group ID)
Also zero-initialize the data array as a defensive measure against similar bugs in the future.
{
"affected": [],
"aliases": [
"CVE-2026-53263"
],
"database_specific": {
"cwe_ids": [
"CWE-193"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-06-25T09:16:44Z",
"severity": "MODERATE"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\n6lowpan: fix off-by-one in multicast context address compression\n\nThe second memcpy in lowpan_iphc_mcast_ctx_addr_compress() uses\n\u0026data[1] as destination and \u0026ipaddr-\u003es6_addr[11] as source, but\nboth should be offset by one: \u0026data[2] and \u0026ipaddr-\u003es6_addr[12]\nrespectively.\n\nThis off-by-one has two consequences:\n1. data[1] is overwritten with s6_addr[11], corrupting the RIID\n field in the compressed multicast address\n2. data[5] is never written, so uninitialized kernel stack memory\n is transmitted over the network via lowpan_push_hc_data(),\n leaking kernel stack contents\n\nThe correct inline data layout must match what the decompression\nfunction lowpan_uncompress_multicast_ctx_daddr() expects:\n data[0..1] = s6_addr[1..2] (flags/scope + RIID)\n data[2..5] = s6_addr[12..15] (group ID)\n\nAlso zero-initialize the data array as a defensive measure against\nsimilar bugs in the future.",
"id": "GHSA-fq9x-8g2w-4p5r",
"modified": "2026-10-15T03:36:18Z",
"published": "2026-06-25T09:31:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53263"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-784472.html"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/06ce6fc106b16dec9b535950db626261be865e5b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2a58899d11009bffc7b4b32a571858f381121837"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4485d79617520d84ba5a14515e2b5136007d6deb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c32f30ef5e66adbfa102348e2e8a23776eb007cb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/da8808463882c3f3c357b072e25053c2121f1419"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/da8cbb64b47e9066b40af0de170901caf17b768c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dcb1bec1c32ee5c3878354e087cf5dbee2b7c7af"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f24a58c72a45f4c109f3557a760cc4b60b7a6037"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
Loading timeline…
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.