{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80839","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-08-26T14:34:25.796Z","datePublished":"2026-09-04T15:54:49.378Z","dateUpdated":"2026-09-04T15:54:49.378Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-04T15:54:49.378Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: reject unrepresentable multicast TVLV offsets\n\nThe network and transport header fields in struct sk_buff are 16-bit\noffsets from skb->head, and U16_MAX is reserved as the unset transport\nheader value. batadv_tvlv_call_handler() sets both fields from a received\nmulticast TVLV without checking whether the TVLV end is representable.\n\nIf the end offset exceeds the field's range, skb_set_transport_header()\ntruncates it so that the transport header precedes the network header.\nThe negative difference is then returned by skb_network_header_len() as\na large u32. batadv_mcast_forw_packet() consequently accepts an oversized\nmulticast tracker and accesses memory beyond the skb data.\n\nAdd skb_set_transport_header_careful(), an offset-aware counterpart to\nskb_reset_transport_header_careful(), which validates the final\nhead-relative offset before assigning it. Use the new helper in\nbatadv_tvlv_call_handler() and reject unrepresentable TVLVs before\nsetting the network header."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/skbuff.h","net/batman-adv/tvlv.c"],"versions":[{"version":"07afe1ba288c04280622fa002ed385f1ac0b6fe6","lessThan":"da1f5aa7ec93f2cc17f5cd30efc54f62af433cf2","status":"affected","versionType":"git"},{"version":"07afe1ba288c04280622fa002ed385f1ac0b6fe6","lessThan":"916ec741e65af072b98e475feaad98c063da1b7c","status":"affected","versionType":"git"},{"version":"07afe1ba288c04280622fa002ed385f1ac0b6fe6","lessThan":"1b466746fe109127fd983100a228cdd1f1f6ece2","status":"affected","versionType":"git"},{"version":"07afe1ba288c04280622fa002ed385f1ac0b6fe6","lessThan":"2b46baa591d0a7c16b62f150917187e70d053be6","status":"affected","versionType":"git"},{"version":"07afe1ba288c04280622fa002ed385f1ac0b6fe6","lessThan":"f12c2de4f542e3220e17e0606f492110064f04cb","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/linux/skbuff.h","net/batman-adv/tvlv.c"],"versions":[{"version":"6.8","status":"affected"},{"version":"0","lessThan":"6.8","status":"unaffected","versionType":"semver"},{"version":"6.12.108","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.49","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.1.13","lessThanOrEqual":"7.1.*","status":"unaffected","versionType":"semver"},{"version":"7.2.3","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.12.108"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"6.18.49"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"7.1.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"7.2.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8","versionEndExcluding":"7.3-rc1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/da1f5aa7ec93f2cc17f5cd30efc54f62af433cf2"},{"url":"https://git.kernel.org/stable/c/916ec741e65af072b98e475feaad98c063da1b7c"},{"url":"https://git.kernel.org/stable/c/1b466746fe109127fd983100a228cdd1f1f6ece2"},{"url":"https://git.kernel.org/stable/c/2b46baa591d0a7c16b62f150917187e70d053be6"},{"url":"https://git.kernel.org/stable/c/f12c2de4f542e3220e17e0606f492110064f04cb"}],"title":"batman-adv: reject unrepresentable multicast TVLV offsets","x_generator":{"engine":"bippy-1.2.0"}}}}