{
  "cveId": "CVE-2026-42772",
  "url": "https://patchblox.com/security/cve/CVE-2026-42772",
  "summary": "CVE-2026-42772 is fixed in 13 products on 1 platform, first by libssl3t64 3.5.5-1ubuntu3.7, released September 29, 2026. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "Potential CPU DoS via O(n^2) Fragment Reassembly in QUIC",
  "description": "Issue summary: The QUIC stream reassembly algorithm performance deteriorates progressively as packets are arriving out of order. The worst case has a quadratic complexity proportional to the number of stream frames kept in the buffer for the received stream data.  Impact summary: A remote QUIC peer that completes the handshake can create a connection-scoped CPU pressure and potentially a Denial of Service using compliant STREAM frames inside the advertised receive window, with low attacker bandwidth.  CWE: CWE-407: Inefficient Algorithmic Complexity  Description: OpenSSL manages received QUIC stream fragments using a doubly-linked list. While it optimizes for append operations (at the end of the list), it falls back to a head-to-tail linear search for any fragment that does not immediately follow the current \u0060tail\u0060.  By manipulating the sequence of offsets, an attacker can force the server to perform O(n^2) operations, consuming excessive CPU time for the QUIC process.  FIPS impact: no The FIPS module is not affected as the QUIC implementation is outside of the OpenSSL FIPS module boundary.",
  "published": "2026-09-29T09:17:00Z",
  "severity": "Moderate",
  "cvss": 5.3,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
  "cwe": "Inefficient Algorithmic Complexity",
  "epss": 0.00497,
  "epssPercentile": 0.42883,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42772",
  "fixes": [
    {
      "platform": "linux",
      "product": "libssl3t64",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "3.5.5-1ubuntu3.7",
      "fix": "libssl3t64 3.5.5-1ubuntu3.7",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-libssl3t64-3.5.5-1ubuntu3.7",
      "released": "2026-09-29T09:17:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "3.5.7-1~deb13u3",
      "fix": "DEBIAN-CVE-2026-42772",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-42772",
      "released": "2026-09-30T20:39:22Z"
    },
    {
      "platform": "linux",
      "product": "openssl",
      "release": "Debian 14",
      "fixedVersion": "3.6.5-1",
      "fix": "DEBIAN-CVE-2026-42772",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-42772",
      "released": "2026-09-30T20:39:22Z"
    },
    {
      "platform": "linux",
      "product": "openssl",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "3.5.5-1ubuntu3.7",
      "fix": "openssl 3.5.5-1ubuntu3.7",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-openssl-3.5.5-1ubuntu3.7",
      "released": "2026-09-29T09:17:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl",
      "release": "amzn 2023",
      "fixedVersion": "1:3.5.8-1.amzn2023.0.3",
      "fix": "ALAS2023-2026-3204",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3204",
      "released": "2026-11-07T01:06:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:3.5.8-1.amzn2023.0.3",
      "fix": "ALAS2023-2026-3204",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3204",
      "released": "2026-11-07T01:06:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl-debugsource",
      "release": "amzn 2023",
      "fixedVersion": "1:3.5.8-1.amzn2023.0.3",
      "fix": "ALAS2023-2026-3204",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3204",
      "released": "2026-11-07T01:06:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl-devel",
      "release": "amzn 2023",
      "fixedVersion": "1:3.5.8-1.amzn2023.0.3",
      "fix": "ALAS2023-2026-3204",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3204",
      "released": "2026-11-07T01:06:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl-fips-provider-latest",
      "release": "amzn 2023",
      "fixedVersion": "1:3.5.8-1.amzn2023.0.3",
      "fix": "ALAS2023-2026-3204",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3204",
      "released": "2026-11-07T01:06:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl-fips-provider-latest-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:3.5.8-1.amzn2023.0.3",
      "fix": "ALAS2023-2026-3204",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3204",
      "released": "2026-11-07T01:06:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl-libs",
      "release": "amzn 2023",
      "fixedVersion": "1:3.5.8-1.amzn2023.0.3",
      "fix": "ALAS2023-2026-3204",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3204",
      "released": "2026-11-07T01:06:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl-libs-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:3.5.8-1.amzn2023.0.3",
      "fix": "ALAS2023-2026-3204",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3204",
      "released": "2026-11-07T01:06:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl-perl",
      "release": "amzn 2023",
      "fixedVersion": "1:3.5.8-1.amzn2023.0.3",
      "fix": "ALAS2023-2026-3204",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3204",
      "released": "2026-11-07T01:06:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl-provider-legacy",
      "release": "Ubuntu 26.04.1 LTS (resolute)",
      "fixedVersion": "3.5.5-1ubuntu3.7",
      "fix": "openssl-provider-legacy 3.5.5-1ubuntu3.7",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-resolute-openssl-provider-legacy-3.5.5-1ubuntu3.7",
      "released": "2026-09-29T09:17:00Z"
    },
    {
      "platform": "linux",
      "product": "openssl-snapsafe-libs",
      "release": "amzn 2023",
      "fixedVersion": "1:3.5.8-1.amzn2023.0.3",
      "fix": "ALAS2023-2026-3204",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3204",
      "released": "2026-11-07T01:06:24Z"
    },
    {
      "platform": "linux",
      "product": "openssl-snapsafe-libs-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1:3.5.8-1.amzn2023.0.3",
      "fix": "ALAS2023-2026-3204",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3204",
      "released": "2026-11-07T01:06:24Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}