{"id":"CVE-2026-70368","state":"PUBLISHED","title":"Stunnel: stack-based out-of-bounds read/write in stunnel s_vlog via oversized log message","description":"A stack-based out-of-bounds read vulnerability exists in the \"s_vlog\" function of stunnel, when handling oversized log messages via \"vsnprintf\". A remote attacker with network access to a stunnel service can send protocol inputs that trigger a log message longer than 1024 bytes, leading to an out-of-bounds stack read and a potential crash. In certain corner cases, the same vulnerability could be used to replace a series of trailing \"\\n\" characters with \"\\0\".","publishedAt":"2026-08-04T13:52:25.255Z","updatedAt":"2026-08-06T07:33:31.694Z","severity":{"score":6.5,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","source":"redhat"},"assigner":"redhat","products":["Mobi-Com Polska Sp. z o.o. stunnel","Red Hat Red Hat Enterprise Linux 10","Red Hat Red Hat Enterprise Linux 6","Red Hat Red Hat Enterprise Linux 7","Red Hat Red Hat Enterprise Linux 8","Red Hat Red Hat Enterprise Linux 9"],"affected":[{"vendor":"Mobi-Com Polska Sp. z o.o.","product":"stunnel","defaultStatus":"unaffected","versions":[{"version":"5.68","status":"affected","lessThan":"5.80","versionType":"custom"}],"repo":"https://github.com/mtrojnar/stunnel"},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","packageName":"stunnel","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","packageName":"stunnel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:6"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","packageName":"stunnel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"stunnel","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"stunnel","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"]}],"references":["https://access.redhat.com/security/cve/CVE-2026-70368","https://bugzilla.redhat.com/show_bug.cgi?id=2462029"],"weaknesses":["CWE-125"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/70xxx/CVE-2026-70368.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-70368","state":"PUBLISHED","datePublished":"2026-08-04T13:52:25.255Z","dateUpdated":"2026-08-06T07:33:31.694Z","assignerShortName":"redhat","assignerOrgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","dateReserved":"2026-08-04T07:03:23.572Z"},"containers":{"cna":{"title":"Stunnel: stack-based out-of-bounds read/write in stunnel s_vlog via oversized log message","descriptions":[{"lang":"en","value":"A stack-based out-of-bounds read vulnerability exists in the \"s_vlog\" function of stunnel, when handling oversized log messages via \"vsnprintf\". A remote attacker with network access to a stunnel service can send protocol inputs that trigger a log message longer than 1024 bytes, leading to an out-of-bounds stack read and a potential crash. In certain corner cases, the same vulnerability could be used to replace a series of trailing \"\\n\" characters with \"\\0\"."}],"affected":[{"vendor":"Mobi-Com Polska Sp. z o.o.","product":"stunnel","defaultStatus":"unaffected","versions":[{"version":"5.68","status":"affected","lessThan":"5.80","versionType":"custom"}],"repo":"https://github.com/mtrojnar/stunnel"},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 10","packageName":"stunnel","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:10"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 6","packageName":"stunnel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:6"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 7","packageName":"stunnel","defaultStatus":"unaffected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:7"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 8","packageName":"stunnel","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:8"]},{"vendor":"Red Hat","product":"Red Hat Enterprise Linux 9","packageName":"stunnel","defaultStatus":"affected","collectionURL":"https://access.redhat.com/downloads/content/package-browser/","cpes":["cpe:/o:redhat:enterprise_linux:9"]}],"references":[{"url":"https://access.redhat.com/security/cve/CVE-2026-70368","tags":["vdb-entry","x_refsource_REDHAT"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2462029","name":"RHBZ#2462029","tags":["issue-tracking","x_refsource_REDHAT"]}],"metrics":[{"other":{"content":{"value":"Moderate","namespace":"https://access.redhat.com/security/updates/classification/"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-125","description":"Out-of-bounds Read","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"redhat","orgId":"53f830b8-0a3f-465b-8143-3b8a9948e749","dateUpdated":"2026-08-06T07:33:31.694Z"},"datePublic":"2026-08-04T10:30:31.438Z","x_redhatCweChain":"CWE-125: Out-of-bounds Read","workarounds":[{"lang":"en","value":"To mitigate this issue, avoid exposing stunnel services to untrusted clients. Restrict access to these services to trusted networks only."}],"timeline":[{"lang":"en","time":"2026-04-26T18:03:12.000Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-08-04T10:30:31.438Z","value":"Made public."}],"credits":[{"lang":"en","value":"This issue was discovered by Found by AISLE in partnership with Red Hat."}],"x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-04T14:21:17.494804Z","id":"CVE-2026-70368","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-04T14:21:27.297Z"}}]}}}