{"api_version":"1","generated_at":"2026-04-19T01:10:18+00:00","cve":"CVE-2026-31427","urls":{"html":"https://cve.report/CVE-2026-31427","api":"https://cve.report/api/cve/CVE-2026-31427.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-31427","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-31427"},"summary":{"title":"netfilter: nf_conntrack_sip: fix use of uninitialized rtp_addr in process_sdp","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_sip: fix use of uninitialized rtp_addr in process_sdp\n\nprocess_sdp() declares union nf_inet_addr rtp_addr on the stack and\npasses it to the nf_nat_sip sdp_session hook after walking the SDP\nmedia descriptions. However rtp_addr is only initialized inside the\nmedia loop when a recognized media type with a non-zero port is found.\n\nIf the SDP body contains no m= lines, only inactive media sections\n(m=audio 0 ...) or only unrecognized media types, rtp_addr is never\nassigned. Despite that, the function still calls hooks->sdp_session()\nwith &rtp_addr, causing nf_nat_sdp_session() to format the stale stack\nvalue as an IP address and rewrite the SDP session owner and connection\nlines with it.\n\nWith CONFIG_INIT_STACK_ALL_ZERO (default on most distributions) this\nresults in the session-level o= and c= addresses being rewritten to\n0.0.0.0 for inactive SDP sessions. Without stack auto-init the\nrewritten address is whatever happened to be on the stack.\n\nFix this by pre-initializing rtp_addr from the session-level connection\naddress (caddr) when available, and tracking via a have_rtp_addr flag\nwhether any valid address was established. Skip the sdp_session hook\nentirely when no valid address exists.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-04-13 14:16:12","updated_at":"2026-04-18 09:16:32"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/6a2b724460cb67caed500c508c2ae5cf012e4db4","name":"https://git.kernel.org/stable/c/6a2b724460cb67caed500c508c2ae5cf012e4db4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/6e5e3c87b7e6212f1d8414fc2e4d158b01e12025","name":"https://git.kernel.org/stable/c/6e5e3c87b7e6212f1d8414fc2e4d158b01e12025","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/7edca70751b9bdb5b83eed53cde21eccf3c86147","name":"https://git.kernel.org/stable/c/7edca70751b9bdb5b83eed53cde21eccf3c86147","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/52fdda318ef2362fc5936385bcb8b3d0328ee629","name":"https://git.kernel.org/stable/c/52fdda318ef2362fc5936385bcb8b3d0328ee629","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/faa6ea32797a1847790514ff0da1be1d09771580","name":"https://git.kernel.org/stable/c/faa6ea32797a1847790514ff0da1be1d09771580","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/01f34a80ac23ae90b1909b94b4ed05343a62f646","name":"https://git.kernel.org/stable/c/01f34a80ac23ae90b1909b94b4ed05343a62f646","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/fe463e76c9b4b0b43b5ee8961b4c500231f1a3f6","name":"https://git.kernel.org/stable/c/fe463e76c9b4b0b43b5ee8961b4c500231f1a3f6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/82baeb871e8f04906bc886273fdf0209e1754eb3","name":"https://git.kernel.org/stable/c/82baeb871e8f04906bc886273fdf0209e1754eb3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-31427","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31427","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4ab9e64e5e3c0516577818804aaf13a630d67bc9 faa6ea32797a1847790514ff0da1be1d09771580 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4ab9e64e5e3c0516577818804aaf13a630d67bc9 82baeb871e8f04906bc886273fdf0209e1754eb3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4ab9e64e5e3c0516577818804aaf13a630d67bc9 6e5e3c87b7e6212f1d8414fc2e4d158b01e12025 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4ab9e64e5e3c0516577818804aaf13a630d67bc9 fe463e76c9b4b0b43b5ee8961b4c500231f1a3f6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 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semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.203 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.168 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.131 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.80 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.21 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.19.11 6.19.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"31427","cve":"CVE-2026-31427","epss":"0.000240000","percentile":"0.066100000","score_date":"2026-04-18","updated_at":"2026-04-19 00:10:43"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/netfilter/nf_conntrack_sip.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"faa6ea32797a1847790514ff0da1be1d09771580","status":"affected","version":"4ab9e64e5e3c0516577818804aaf13a630d67bc9","versionType":"git"},{"lessThan":"82baeb871e8f04906bc886273fdf0209e1754eb3","status":"affected","version":"4ab9e64e5e3c0516577818804aaf13a630d67bc9","versionType":"git"},{"lessThan":"6e5e3c87b7e6212f1d8414fc2e4d158b01e12025","status":"affected","version":"4ab9e64e5e3c0516577818804aaf13a630d67bc9","versionType":"git"},{"lessThan":"fe463e76c9b4b0b43b5ee8961b4c500231f1a3f6","status":"affected","version":"4ab9e64e5e3c0516577818804aaf13a630d67bc9","versionType":"git"},{"lessThan":"7edca70751b9bdb5b83eed53cde21eccf3c86147","status":"affected","version":"4ab9e64e5e3c0516577818804aaf13a630d67bc9","versionType":"git"},{"lessThan":"01f34a80ac23ae90b1909b94b4ed05343a62f646","status":"affected","version":"4ab9e64e5e3c0516577818804aaf13a630d67bc9","versionType":"git"},{"lessThan":"52fdda318ef2362fc5936385bcb8b3d0328ee629","status":"affected","version":"4ab9e64e5e3c0516577818804aaf13a630d67bc9","versionType":"git"},{"lessThan":"6a2b724460cb67caed500c508c2ae5cf012e4db4","status":"affected","version":"4ab9e64e5e3c0516577818804aaf13a630d67bc9","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/netfilter/nf_conntrack_sip.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.26"},{"lessThan":"2.6.26","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.253","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.203","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.168","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.131","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.80","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.21","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.11","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.253","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.203","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.168","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.131","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.80","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.21","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.11","versionStartIncluding":"2.6.26","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0","versionStartIncluding":"2.6.26","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_sip: fix use of uninitialized rtp_addr in process_sdp\n\nprocess_sdp() declares union nf_inet_addr rtp_addr on the stack and\npasses it to the nf_nat_sip sdp_session hook after walking the SDP\nmedia descriptions. However rtp_addr is only initialized inside the\nmedia loop when a recognized media type with a non-zero port is found.\n\nIf the SDP body contains no m= lines, only inactive media sections\n(m=audio 0 ...) or only unrecognized media types, rtp_addr is never\nassigned. Despite that, the function still calls hooks->sdp_session()\nwith &rtp_addr, causing nf_nat_sdp_session() to format the stale stack\nvalue as an IP address and rewrite the SDP session owner and connection\nlines with it.\n\nWith CONFIG_INIT_STACK_ALL_ZERO (default on most distributions) this\nresults in the session-level o= and c= addresses being rewritten to\n0.0.0.0 for inactive SDP sessions. Without stack auto-init the\nrewritten address is whatever happened to be on the stack.\n\nFix this by pre-initializing rtp_addr from the session-level connection\naddress (caddr) when available, and tracking via a have_rtp_addr flag\nwhether any valid address was established. Skip the sdp_session hook\nentirely when no valid address exists."}],"providerMetadata":{"dateUpdated":"2026-04-18T08:59:42.607Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/faa6ea32797a1847790514ff0da1be1d09771580"},{"url":"https://git.kernel.org/stable/c/82baeb871e8f04906bc886273fdf0209e1754eb3"},{"url":"https://git.kernel.org/stable/c/6e5e3c87b7e6212f1d8414fc2e4d158b01e12025"},{"url":"https://git.kernel.org/stable/c/fe463e76c9b4b0b43b5ee8961b4c500231f1a3f6"},{"url":"https://git.kernel.org/stable/c/7edca70751b9bdb5b83eed53cde21eccf3c86147"},{"url":"https://git.kernel.org/stable/c/01f34a80ac23ae90b1909b94b4ed05343a62f646"},{"url":"https://git.kernel.org/stable/c/52fdda318ef2362fc5936385bcb8b3d0328ee629"},{"url":"https://git.kernel.org/stable/c/6a2b724460cb67caed500c508c2ae5cf012e4db4"}],"title":"netfilter: nf_conntrack_sip: fix use of uninitialized rtp_addr in process_sdp","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-31427","datePublished":"2026-04-13T13:40:30.280Z","dateReserved":"2026-03-09T15:48:24.088Z","dateUpdated":"2026-04-18T08:59:42.607Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-04-13 14:16:12","lastModifiedDate":"2026-04-18 09:16:32","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"31427","Ordinal":"1","Title":"netfilter: nf_conntrack_sip: fix use of uninitialized rtp_addr i","CVE":"CVE-2026-31427","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"31427","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_sip: fix use of uninitialized rtp_addr in process_sdp\n\nprocess_sdp() declares union nf_inet_addr rtp_addr on the stack and\npasses it to the nf_nat_sip sdp_session hook after walking the SDP\nmedia descriptions. However rtp_addr is only initialized inside the\nmedia loop when a recognized media type with a non-zero port is found.\n\nIf the SDP body contains no m= lines, only inactive media sections\n(m=audio 0 ...) or only unrecognized media types, rtp_addr is never\nassigned. Despite that, the function still calls hooks->sdp_session()\nwith &rtp_addr, causing nf_nat_sdp_session() to format the stale stack\nvalue as an IP address and rewrite the SDP session owner and connection\nlines with it.\n\nWith CONFIG_INIT_STACK_ALL_ZERO (default on most distributions) this\nresults in the session-level o= and c= addresses being rewritten to\n0.0.0.0 for inactive SDP sessions. Without stack auto-init the\nrewritten address is whatever happened to be on the stack.\n\nFix this by pre-initializing rtp_addr from the session-level connection\naddress (caddr) when available, and tracking via a have_rtp_addr flag\nwhether any valid address was established. Skip the sdp_session hook\nentirely when no valid address exists.","Type":"Description","Title":"netfilter: nf_conntrack_sip: fix use of uninitialized rtp_addr i"}]}}}