CVE-2026-80839batman-adv: reject unrepresentable multicast TVLV offsets
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: batman-adv: reject unrepresentable multicast TVLV offsets The network and transport header fields in struct sk_buff are 16-bit offsets from skb->head, and U16_MAX is reserved as the unset transport header value. batadv_tvlv_call_handler() sets both fields from a received multicast TVLV without checking whether the TVLV end is representable. If the end offset exceeds the field's range, skb_set_transport_header() truncates it so that the transport header precedes the network header. The negative difference is then returned by skb_network_header_len() as a large u32. batadv_mcast_forw_packet() consequently accepts an oversized multicast tracker and accesses memory beyond the skb data. Add skb_set_transport_header_careful(), an offset-aware counterpart to skb_reset_transport_header_careful(), which validates the final head-relative offset before assigning it. Use the new helper in batadv_tvlv_call_handler() and reject unrepresentable TVLVs before setting the network header.
- CVSS
- Not yet scored
- 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
- Received
- Record last updated
- Sep 4, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 07afe1ba288c04280622fa002ed385f1ac0b6fe6 before da1f5aa7ec93f2cc17f5cd30efc54f62af433cf2; from 07afe1ba288c04280622fa002ed385f1ac0b6fe6 before 916ec741e65af072b98e475feaad98c063da1b7c; 07afe1ba288c04280622fa002ed385f1ac0b6fe6 builds before 1b466746fe109127fd983100a228cdd1f1f6ece2; 07afe1ba288c04280622fa002ed385f1ac0b6fe6 builds before 2b46baa591d0a7c16b62f150917187e70d053be6; from 07afe1ba288c04280622fa002ed385f1ac0b6fe6 before f12c2de4f542e3220e17e0606f492110064f04cb | CNA record |
References
- https://git.kernel.org/stable/c/da1f5aa7ec93f2cc17f5cd30efc54f62af433cf2
- https://git.kernel.org/stable/c/916ec741e65af072b98e475feaad98c063da1b7c
- https://git.kernel.org/stable/c/1b466746fe109127fd983100a228cdd1f1f6ece2
- https://git.kernel.org/stable/c/2b46baa591d0a7c16b62f150917187e70d053be6
- https://git.kernel.org/stable/c/f12c2de4f542e3220e17e0606f492110064f04cb
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.