{"id":"CVE-2026-45843","state":"PUBLISHED","title":"slip: bound decode() reads against the compressed packet length","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nslip: bound decode() reads against the compressed packet length\n\nslhc_uncompress() parses a VJ-compressed TCP header by advancing a\npointer through the packet via decode() and pull16(). Neither helper\nbounds-checks against isize, and decode() masks its return with\n& 0xffff so it can never return the -1 that callers test for -- those\nerror paths are dead code.\n\nA short compressed frame whose change byte requests optional fields\nlets decode() read past the end of the packet. The over-read bytes\nare folded into the cached cstate and reflected into subsequent\nreconstructed packets.\n\nMake decode() and pull16() take the packet end pointer and return -1\nwhen exhausted. Add a bounds check before the TCP-checksum read.\nThe existing == -1 tests now do what they were always meant to.","publishedAt":"2026-05-27T09:24:45.516Z","updatedAt":"2026-10-19T19:26:38.168Z","severity":{"score":8.2,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6268f01ae989013671b526c883e92655342c6f6f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"9aafba2f49e1fcccc2018816f5836a609c925879","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"335957df4ed60f02a2ec0432fbedbf0cc7241d8b","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"37537e42e6df387398bee85cb85070cc80bb1e10","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"4cefe32639933d652614b0bd50f818f9af4af78f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"0511ecb00e61bf28e2fec4bb41fcce385c3a3b2d","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"d42bec6e4f6d6d658be365539400b3314b76b2a7","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"4c1367a2d7aad643a6f87c6931b13cc1a25e8ca7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/slip/slhc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/slip/slhc.c"]}],"references":["https://git.kernel.org/stable/c/6268f01ae989013671b526c883e92655342c6f6f","https://git.kernel.org/stable/c/9aafba2f49e1fcccc2018816f5836a609c925879","https://git.kernel.org/stable/c/335957df4ed60f02a2ec0432fbedbf0cc7241d8b","https://git.kernel.org/stable/c/37537e42e6df387398bee85cb85070cc80bb1e10","https://git.kernel.org/stable/c/4cefe32639933d652614b0bd50f818f9af4af78f","https://git.kernel.org/stable/c/0511ecb00e61bf28e2fec4bb41fcce385c3a3b2d","https://git.kernel.org/stable/c/d42bec6e4f6d6d658be365539400b3314b76b2a7","https://git.kernel.org/stable/c/4c1367a2d7aad643a6f87c6931b13cc1a25e8ca7","https://cert-portal.siemens.com/productcert/html/ssa-784472.html"],"weaknesses":["CWE-126"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/45xxx/CVE-2026-45843.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45843","state":"PUBLISHED","datePublished":"2026-05-27T09:24:45.516Z","dateUpdated":"2026-10-19T19:26:38.168Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.078Z"},"containers":{"cna":{"title":"slip: bound decode() reads against the compressed packet length","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nslip: bound decode() reads against the compressed packet length\n\nslhc_uncompress() parses a VJ-compressed TCP header by advancing a\npointer through the packet via decode() and pull16(). Neither helper\nbounds-checks against isize, and decode() masks its return with\n& 0xffff so it can never return the -1 that callers test for -- those\nerror paths are dead code.\n\nA short compressed frame whose change byte requests optional fields\nlets decode() read past the end of the packet. The over-read bytes\nare folded into the cached cstate and reflected into subsequent\nreconstructed packets.\n\nMake decode() and pull16() take the packet end pointer and return -1\nwhen exhausted. Add a bounds check before the TCP-checksum read.\nThe existing == -1 tests now do what they were always meant to."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"6268f01ae989013671b526c883e92655342c6f6f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"9aafba2f49e1fcccc2018816f5836a609c925879","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"335957df4ed60f02a2ec0432fbedbf0cc7241d8b","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"37537e42e6df387398bee85cb85070cc80bb1e10","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"4cefe32639933d652614b0bd50f818f9af4af78f","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"0511ecb00e61bf28e2fec4bb41fcce385c3a3b2d","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"d42bec6e4f6d6d658be365539400b3314b76b2a7","versionType":"git"},{"version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","status":"affected","lessThan":"4c1367a2d7aad643a6f87c6931b13cc1a25e8ca7","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/slip/slhc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.12","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.12","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.33","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.10","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/slip/slhc.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/6268f01ae989013671b526c883e92655342c6f6f"},{"url":"https://git.kernel.org/stable/c/9aafba2f49e1fcccc2018816f5836a609c925879"},{"url":"https://git.kernel.org/stable/c/335957df4ed60f02a2ec0432fbedbf0cc7241d8b"},{"url":"https://git.kernel.org/stable/c/37537e42e6df387398bee85cb85070cc80bb1e10"},{"url":"https://git.kernel.org/stable/c/4cefe32639933d652614b0bd50f818f9af4af78f"},{"url":"https://git.kernel.org/stable/c/0511ecb00e61bf28e2fec4bb41fcce385c3a3b2d"},{"url":"https://git.kernel.org/stable/c/d42bec6e4f6d6d658be365539400b3314b76b2a7"},{"url":"https://git.kernel.org/stable/c/4c1367a2d7aad643a6f87c6931b13cc1a25e8ca7"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N","baseScore":8.2,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - slhc_uncompress() processes VJ-compressed headers received from the remote PPP/SLIP link peer; via PPP-over-PPTP/L2TP tunnels that peer is an internet-reachable attacker sending crafted frames.\nAC:L - A short compressed frame with a change byte requesting optional fields reliably triggers the over-read; no race, timing, or memory-layout condition outside the attacker's control.\nPR:N - The attacker is a remote link peer (e.g., malicious VPN/dial-up server, or a client of the target's PPTP/L2TP server) with no account or privilege on the target host.\nUI:N - Once a VJ-enabled PPP link exists, the malicious frame is processed automatically; in the attacker-initiated server scenario no victim action is needed at exploit time.\nS:U - The over-read and its effects stay within the kernel's own decompression buffers and state; no crossing into another security authority.\nC:H - Out-of-bounds read of adjacent memory — including uninitialized kernel slab memory in the PPP fresh-skb path — folded into reconstructed TCP/IP header fields delivered to the IP stack, disclosing kernel memory.\nI:L - The over-read pollutes the cached decompression state (cs_tcp/cs_ip) and corrupts header fields of subsequently reconstructed packets with stale data, but yields no arbitrary or out-of-bounds write primitive.\nA:N - Guaranteed buffer slack plus the len<0 rejection keep all reads within the allocation and prevent any out-of-bounds write, so there is no crash, hang, or panic."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:28:27.680Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.12","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 TM MFP - GNU/Linux subsystem","defaultStatus":"unknown","versions":[{"version":"0","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:19:46.866Z"},"x_adpType":"supplier"},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-45843","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-10-16T15:17:54.838787Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-126","lang":"en","type":"CWE","description":"CWE-126 Buffer Over-read"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T19:26:38.168Z"}}]}}}