{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-52986","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-06-09T07:44:35.376Z","datePublished":"2026-06-24T16:29:00.752Z","dateUpdated":"2026-08-05T12:32:22.474Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:32:22.474Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: nf_conntrack_sip: don't use simple_strtoul\n\nReplace unsafe port parsing in epaddr_len(), ct_sip_parse_header_uri(),\nand ct_sip_parse_request() with a new sip_parse_port() helper that\nvalidates each digit against the buffer limit, eliminating the use of\nsimple_strtoul() which assumes NUL-terminated strings.\n\nThe previous code dereferenced pointers without bounds checks after\nsip_parse_addr() and relied on simple_strtoul() on non-NUL-terminated\nskb data. A port that reaches the buffer limit without a trailing\ncharacter is also rejected as malformed.\n\nAlso get rid of all simple_strtoul() usage in conntrack, prefer a\nstricter version instead.  There are intentional changes:\n\n- Bail out if number is > UINT_MAX and indicate a failure, same for\n  too long sequences.\n  While we do accept 05535 as port 5535, we will not accept e.g.\n  'sip:10.0.0.1:005060'.  While its syntactically valid under RFC 3261,\n  we should restrict this to not waste cycles when presented with\n  malformed packets with 64k '0' characters.\n\n- Force base 10 in ct_sip_parse_numerical_param(). This is used to fetch\n  'expire=' and 'rports='; both are expected to use base-10.\n\n- In nf_nat_sip.c, only accept the parsed value if its within the 1k-64k\n  range.\n\n- epaddr_len now returns 0 if the port is invalid, as it already does\n  for invalid ip addresses.  This is intentional. nf_conntrack_sip\n  performs lots of guesswork to find the right parts of the message\n  to parse.  Being stricter could break existing setups.\n  Connection tracking helpers are designed to allow traffic to\n  pass, not to block it.\n\nBased on an earlier patch from Jenny Guanni Qu <qguanni@gmail.com>."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable SIP conntrack helper parses SIP payload carried in TCP/UDP network packets once the SIP helper is enabled, which is a reasonable deployment for NAT/firewall SIP gateways. A remote SIP peer can send crafted packets to that packet-processing path.\nAC:L - The trigger is a malformed numeric SIP field or URI port at the parser buffer boundary; no race or victim-controlled timing is required. Helper/NAT configuration is an environmental prerequisite, not an attacker-controlled complexity condition.\nPR:N - In the network gateway scenario, the attacker only needs to send unauthenticated SIP traffic through a system using the SIP conntrack helper. No local account or kernel privilege is required.\nUI:N - Exploitation is driven by packet processing in netfilter/conntrack. No user action is needed after the affected helper is configured.\nS:U - The impact is within the kernel/network stack security authority of the vulnerable system. It does not cross a separate scope such as guest-to-host or IOMMU isolation.\nC:H - The bug is an unbounded out-of-bounds read from non-NUL-terminated skb data via simple_strtoul and missing limit checks. Following the required guidance, an unbounded OOB read is high confidentiality impact.\nI:H - In NATed SIP paths, an out-of-bounds parser end pointer can feed attacker-influenced match lengths into NAT packet mangling, whose memmove/memcpy path lacks a bounds check against the skb payload. That creates a defensible kernel memory-corruption/code-execution risk.\nA:H - The same OOB read and possible invalid NAT mangle lengths can cause kernel faults, skb corruption, or panic. Crafted packets can be sent repeatedly, so availability impact is high."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_conntrack_sip.c","net/netfilter/nf_nat_sip.c"],"versions":[{"version":"05e3ced297fe755093140e7487e292fb7603316e","lessThan":"8cd0358379570003659186706e077929d6930c40","status":"affected","versionType":"git"},{"version":"05e3ced297fe755093140e7487e292fb7603316e","lessThan":"9c6afcb1c3cbb2c0da65b8515ac14d7273872f84","status":"affected","versionType":"git"},{"version":"05e3ced297fe755093140e7487e292fb7603316e","lessThan":"b3264c977e79d8a25778d4fd11520f00fea1329c","status":"affected","versionType":"git"},{"version":"05e3ced297fe755093140e7487e292fb7603316e","lessThan":"ea2ecd29b8f4433e52607192ca91084f95787ca0","status":"affected","versionType":"git"},{"version":"05e3ced297fe755093140e7487e292fb7603316e","lessThan":"9f69c323ae0ab517e595c2cc74e0ae0d9d085611","status":"affected","versionType":"git"},{"version":"05e3ced297fe755093140e7487e292fb7603316e","lessThan":"7df9863bf538a626e8a684e59cb2c43eac0ef3c8","status":"affected","versionType":"git"},{"version":"05e3ced297fe755093140e7487e292fb7603316e","lessThan":"523762e3b6933fff81f01dfa3c60c0774044cdab","status":"affected","versionType":"git"},{"version":"05e3ced297fe755093140e7487e292fb7603316e","lessThan":"8cf6809cddcbe301aedfc6b51bcd4944d45795f6","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_conntrack_sip.c","net/netfilter/nf_nat_sip.c"],"versions":[{"version":"2.6.26","status":"affected"},{"version":"0","lessThan":"2.6.26","status":"unaffected","versionType":"semver"},{"version":"5.10.258","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.209","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.175","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.141","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.91","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.33","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.10","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","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":"2.6.26","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.26","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/8cd0358379570003659186706e077929d6930c40"},{"url":"https://git.kernel.org/stable/c/9c6afcb1c3cbb2c0da65b8515ac14d7273872f84"},{"url":"https://git.kernel.org/stable/c/b3264c977e79d8a25778d4fd11520f00fea1329c"},{"url":"https://git.kernel.org/stable/c/ea2ecd29b8f4433e52607192ca91084f95787ca0"},{"url":"https://git.kernel.org/stable/c/9f69c323ae0ab517e595c2cc74e0ae0d9d085611"},{"url":"https://git.kernel.org/stable/c/7df9863bf538a626e8a684e59cb2c43eac0ef3c8"},{"url":"https://git.kernel.org/stable/c/523762e3b6933fff81f01dfa3c60c0774044cdab"},{"url":"https://git.kernel.org/stable/c/8cf6809cddcbe301aedfc6b51bcd4944d45795f6"}],"title":"netfilter: nf_conntrack_sip: don't use simple_strtoul","x_generator":{"engine":"bippy-1.2.0"}}}}