{
  "threat_severity" : "Moderate",
  "public_date" : "2026-08-04T10:30:31Z",
  "bugzilla" : {
    "description" : "stunnel: Stack-based out-of-bounds read/write in stunnel s_vlog via oversized log message",
    "id" : "2462029",
    "url" : "https://bugzilla.redhat.com/show_bug.cgi?id=2462029"
  },
  "cvss3" : {
    "cvss3_base_score" : "6.5",
    "cvss3_scoring_vector" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L",
    "status" : "draft"
  },
  "cwe" : "CWE-125",
  "details" : [ "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\".", "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\"." ],
  "statement" : "This Moderate impact vulnerability affects stunnel services if their configuration allows long attacker-controlled log messages. Server-side IMAP protocol negotiation (\"protocol = imap\") is known to be affected, where a remote, unauthenticated attacker can trigger a denial-of-service by sending an oversized IMAP command. Reliable integrity impact or code execution as a result of this issue would be very difficult and likely impractical. This issue specifically affects \"stunnel\" 5.79 and lower when exposed to untrusted networks.",
  "acknowledgement" : "This issue was discovered by Found by AISLE in partnership with Red Hat.",
  "package_state" : [ {
    "product_name" : "Red Hat Enterprise Linux 10",
    "fix_state" : "Fix deferred",
    "package_name" : "stunnel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:10"
  }, {
    "product_name" : "Red Hat Enterprise Linux 6",
    "fix_state" : "Not affected",
    "package_name" : "stunnel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:6"
  }, {
    "product_name" : "Red Hat Enterprise Linux 7",
    "fix_state" : "Not affected",
    "package_name" : "stunnel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:7"
  }, {
    "product_name" : "Red Hat Enterprise Linux 8",
    "fix_state" : "Fix deferred",
    "package_name" : "stunnel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:8"
  }, {
    "product_name" : "Red Hat Enterprise Linux 9",
    "fix_state" : "Fix deferred",
    "package_name" : "stunnel",
    "cpe" : "cpe:/o:redhat:enterprise_linux:9"
  } ],
  "references" : [ "https://www.cve.org/CVERecord?id=CVE-2026-70368\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-70368" ],
  "name" : "CVE-2026-70368",
  "mitigation" : {
    "value" : "To mitigate this issue, avoid exposing stunnel services to untrusted clients. Restrict access to these services to trusted networks only.",
    "lang" : "en:us"
  },
  "csaw" : false
}