{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-39931", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.147Z", "datePublished": "2025-10-04T07:30:55.964Z", "dateUpdated": "2026-08-05T12:06:10.490Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:06:10.490Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: af_alg - Set merge to zero early in af_alg_sendmsg\n\nIf an error causes af_alg_sendmsg to abort, ctx->merge may contain\na garbage value from the previous loop. This may then trigger a\ncrash on the next entry into af_alg_sendmsg when it attempts to do\na merge that can't be done.\n\nFix this by setting ctx->merge to zero near the start of the loop." } ], "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 - AF_ALG is a local kernel-crypto socket interface reached via socket()/bind()/sendmsg() syscalls; there is no network exposure. Exploitation requires a local account to issue the syscalls.\nAC:L - The attacker controls both the error-aborting sendmsg (a fault in memcpy_from_msg or a forced allocation error is trivially induced) and the subsequent merge-triggering sendmsg, so the condition is reliably created; heap grooming for full exploitation is also within attacker control.\nPR:L - Creating and driving an AF_ALG socket requires no capabilities and passes no privilege check, so any basic unprivileged local user can reach the vulnerable path.\nUI:N - The entire sequence is performed by the attacker's own process with no victim action required.\nS:U - The corruption stays within the kernel's own security authority (standard local privilege escalation); no VM/IOMMU/sandbox boundary is crossed.\nC:H - The stale merge flag causes an out-of-bounds scatterlist read and a heap write primitive that can be leveraged to disclose kernel memory contents.\nI:H - The merge path performs an attacker-controlled write to an address derived from an out-of-bounds-read scatterlist entry, giving a heap out-of-bounds write suitable for control-flow hijacking/privilege escalation.\nA:H - The inconsistent tsgl state and wild write reliably cause kernel memory corruption and panic/oops." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "crypto/af_alg.c" ], "versions": [ { "version": "8ff590903d5fc7f5a0a988c38267a3d08e6393a2", "lessThan": "28f6f37abca7c5c9eb3959c66310f1d4d98b8aaf", "status": "affected", "versionType": "git" }, { "version": "8ff590903d5fc7f5a0a988c38267a3d08e6393a2", "lessThan": "db2b42425dfbde4983b0c20fb7cfa05f70e6a745", "status": "affected", "versionType": "git" }, { "version": "8ff590903d5fc7f5a0a988c38267a3d08e6393a2", "lessThan": "6241b9e2809b12da9130894cf5beddf088dc1b8a", "status": "affected", "versionType": "git" }, { "version": "8ff590903d5fc7f5a0a988c38267a3d08e6393a2", "lessThan": "2374c11189ef704a3e4863646369f1b8e6a27d71", "status": "affected", "versionType": "git" }, { "version": "8ff590903d5fc7f5a0a988c38267a3d08e6393a2", "lessThan": "24c1106504c625fabd3b7229611af617b4c27ac7", "status": "affected", "versionType": "git" }, { "version": "8ff590903d5fc7f5a0a988c38267a3d08e6393a2", "lessThan": "045ee26aa3920a47ec46d7fcb302420bf01fd753", "status": "affected", "versionType": "git" }, { "version": "8ff590903d5fc7f5a0a988c38267a3d08e6393a2", "lessThan": "9574b2330dbd2b5459b74d3b5e9619d39299fc6f", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "crypto/af_alg.c" ], "versions": [ { "version": "2.6.38", "status": "affected" }, { "version": "0", "lessThan": "2.6.38", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.260", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.211", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.154", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.108", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.49", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16.9", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17", "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": "2.6.38", "versionEndExcluding": "5.10.260" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "5.15.211" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.1.154" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.6.108" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.12.49" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.16.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.38", "versionEndExcluding": "6.17" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/28f6f37abca7c5c9eb3959c66310f1d4d98b8aaf" }, { "url": "https://git.kernel.org/stable/c/db2b42425dfbde4983b0c20fb7cfa05f70e6a745" }, { "url": "https://git.kernel.org/stable/c/6241b9e2809b12da9130894cf5beddf088dc1b8a" }, { "url": "https://git.kernel.org/stable/c/2374c11189ef704a3e4863646369f1b8e6a27d71" }, { "url": "https://git.kernel.org/stable/c/24c1106504c625fabd3b7229611af617b4c27ac7" }, { "url": "https://git.kernel.org/stable/c/045ee26aa3920a47ec46d7fcb302420bf01fd753" }, { "url": "https://git.kernel.org/stable/c/9574b2330dbd2b5459b74d3b5e9619d39299fc6f" } ], "title": "crypto: af_alg - Set merge to zero early in af_alg_sendmsg", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-07-14T12:43:06.472Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.5", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" }, { "vendor": "Siemens", "product": "SIPLUS S7-1500 CPU 1518-4 PN/DP MFP", "versions": [ { "status": "affected", "version": "V3.1.6", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html" }, { "url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html" } ] } ] } }