CVE-2026-532636lowpan: fix off-by-one in multicast context address compression
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In 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.
- CVSS
- 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Modified
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 5609c185f24dffca5f6a9c127106869da150be03 before f24a58c72a45f4c109f3557a760cc4b60b7a6037; from 5609c185f24dffca5f6a9c127106869da150be03 before da8cbb64b47e9066b40af0de170901caf17b768c; 5609c185f24dffca5f6a9c127106869da150be03 builds before 4485d79617520d84ba5a14515e2b5136007d6deb; 5609c185f24dffca5f6a9c127106869da150be03 builds before 06ce6fc106b16dec9b535950db626261be865e5b; from 5609c185f24dffca5f6a9c127106869da150be03 before dcb1bec1c32ee5c3878354e087cf5dbee2b7c7af; from 5609c185f24dffca5f6a9c127106869da150be03 before c32f30ef5e66adbfa102348e2e8a23776eb007cb; from 5609c185f24dffca5f6a9c127106869da150be03 before da8808463882c3f3c357b072e25053c2121f1419; 5609c185f24dffca5f6a9c127106869da150be03 builds before 2a58899d11009bffc7b4b32a571858f381121837 | CNA record |
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem siemens:simatic_s7_1500_tm_mfp_gnu_linux_subsystem (from the name) | all versions | CISA ADP |
linux linux_kernel linux:linux_kernel | from 4.6 before 5.10.259; from 5.11 before 5.15.210; from 5.16 before 6.1.176; from 6.2 before 6.6.143; from 6.7 before 6.12.94; from 6.13 before 6.18.36; from 6.19 before 7.0.13; 7.1; and 5 more ranges | NVD |
References
- https://git.kernel.org/stable/c/f24a58c72a45f4c109f3557a760cc4b60b7a6037patch
- https://git.kernel.org/stable/c/da8cbb64b47e9066b40af0de170901caf17b768cpatch
- https://git.kernel.org/stable/c/4485d79617520d84ba5a14515e2b5136007d6debpatch
- https://git.kernel.org/stable/c/06ce6fc106b16dec9b535950db626261be865e5bpatch
- https://git.kernel.org/stable/c/dcb1bec1c32ee5c3878354e087cf5dbee2b7c7afpatch
- https://git.kernel.org/stable/c/c32f30ef5e66adbfa102348e2e8a23776eb007cbpatch
- https://git.kernel.org/stable/c/da8808463882c3f3c357b072e25053c2121f1419patch
- https://git.kernel.org/stable/c/2a58899d11009bffc7b4b32a571858f381121837patch
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.