{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-31630", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.124Z", "datePublished": "2026-04-24T14:44:46.606Z", "dateUpdated": "2026-08-05T12:23:56.503Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:23:56.503Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: proc: size address buffers for %pISpc output\n\nThe AF_RXRPC procfs helpers format local and remote socket addresses into\nfixed 50-byte stack buffers with \"%pISpc\".\n\nThat is too small for the longest current-tree IPv6-with-port form the\nformatter can produce. In lib/vsprintf.c, the compressed IPv6 path uses a\ndotted-quad tail not only for v4mapped addresses, but also for ISATAP\naddresses via ipv6_addr_is_isatap().\n\nAs a result, a case such as\n\n [ffff:ffff:ffff:ffff:0:5efe:255.255.255.255]:65535\n\nis possible with the current formatter. That is 50 visible characters, so\n51 bytes including the trailing NUL, which does not fit in the existing\nchar[50] buffers used by net/rxrpc/proc.c.\n\nSize the buffers from the formatter's maximum textual form and switch the\ncall sites to scnprintf().\n\nChanges since v1:\n- correct the changelog to cite the actual maximum current-tree case\n explicitly\n- frame the proof around the ISATAP formatting path instead of the earlier\n mapped-v4 example" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The overflowing sprintf is executed when a local process reads the world-readable RXRPC procfs seq files under /proc/net/rxrpc. A remote RXRPC peer can influence stored addresses on a listening service, but cannot directly invoke the proc show path without a local proc read.\nAC:L - No race or hard-to-control timing is required; an attacker can create or cause an RXRPC IPv6 peer/address with the maximal ISATAP-style textual form and read the proc entry. The overflow condition is deterministic once such an address is present.\nPR:L - The proc entries are created mode 0444 and RXRPC socket creation/sendmsg paths do not impose a capability check, so a basic unprivileged local user can reach the vulnerable show functions. This does not require real root or init-namespace administrative privileges.\nUI:N - The attacker can trigger the vulnerable formatting by reading the proc file themselves. No separate victim action is required.\nS:U - The bug corrupts kernel memory within the same kernel security authority. It is not a VM escape, IOMMU bypass, or cross-scope boundary violation.\nC:H - The bug is kernel stack memory corruption from an out-of-bounds write in attacker-reachable code. Following the higher-severity rule for memory corruption, successful exploitation could compromise kernel confidentiality.\nI:H - The vulnerable sprintf writes past a fixed stack buffer, giving an out-of-bounds kernel stack write. Under the required scoring guidance, out-of-bounds writes are treated as high integrity impact due to potential control-flow or kernel state corruption.\nA:H - Even if not shaped into code execution, the stack corruption can produce an oops, panic, or other kernel crash. The attacker can retrigger it repeatedly by reading the affected proc entries while the crafted address object exists." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/rxrpc/proc.c" ], "versions": [ { "version": "75b54cb57ca34cbe7a87c6ac757c55360a624590", "lessThan": "386c86412608d3449006a318a662cbcd6ca1f668", "status": "affected", "versionType": "git" }, { "version": "75b54cb57ca34cbe7a87c6ac757c55360a624590", "lessThan": "235b2115de892eab2e107a42efa7a4347baaa80b", "status": "affected", "versionType": "git" }, { "version": "75b54cb57ca34cbe7a87c6ac757c55360a624590", "lessThan": "625af53a1564e31bb2df9adc3739df46137f46c1", "status": "affected", "versionType": "git" }, { "version": "75b54cb57ca34cbe7a87c6ac757c55360a624590", "lessThan": "db297c78ce537c9ac96f0eda9b25ad72c8caefa9", "status": "affected", "versionType": "git" }, { "version": "75b54cb57ca34cbe7a87c6ac757c55360a624590", "lessThan": "10ebed83f9f6414af4e85bc85ffaeda7effdd874", "status": "affected", "versionType": "git" }, { "version": "75b54cb57ca34cbe7a87c6ac757c55360a624590", "lessThan": "a44ce6aa2efb61fe44f2cfab72bb01544bbca272", "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/rxrpc/proc.c" ], "versions": [ { "version": "4.9", "status": "affected" }, { "version": "0", "lessThan": "4.9", "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": "6.18.23", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19.13", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.0", "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": "4.9", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.18.23" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "6.19.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.9", "versionEndExcluding": "7.0" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/386c86412608d3449006a318a662cbcd6ca1f668" }, { "url": "https://git.kernel.org/stable/c/235b2115de892eab2e107a42efa7a4347baaa80b" }, { "url": "https://git.kernel.org/stable/c/625af53a1564e31bb2df9adc3739df46137f46c1" }, { "url": "https://git.kernel.org/stable/c/db297c78ce537c9ac96f0eda9b25ad72c8caefa9" }, { "url": "https://git.kernel.org/stable/c/10ebed83f9f6414af4e85bc85ffaeda7effdd874" }, { "url": "https://git.kernel.org/stable/c/a44ce6aa2efb61fe44f2cfab72bb01544bbca272" } ], "title": "rxrpc: proc: size address buffers for %pISpc output", "x_generator": { "engine": "bippy-1.2.0" } } } }