{
  "cveId": "CVE-2026-15957",
  "url": "https://patchblox.com/security/cve/CVE-2026-15957",
  "summary": "CVE-2026-15957 is fixed in 4 products on 1 platform, first by ALAS2023-2026-3116, released September 28, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "network-flow-monitor-agent-debuginfo: Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities:\nCVE-2026-53587:\n\tlibgit2...",
  "description": "Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities:\nCVE-2026-53587:\n\tlibgit2 version 1.9.4 and below is vulnerable to a heap out-of-bounds read in set_data() in src/libgit2/transports/smart_pkt.c.\n\nThe vulnerable code uses a fixed-size strncmp (smart_pkt.c:239) against the unvalidated capability buffer of a smart-protocol pkt-line. When the bytes following the pkt-line in the contiguous receive buffer happen to continue with \u0022ct-format=\u0022, the comparison spuriously matches, advancing format_str past the pkt-line boundary. The following memchr(format_str, \u0027 \u0027, len - (format_str - line)) (smart_pkt.c:246) then underflows its size_t size argument to ~SIZE_MAX and walks the heap looking for a space byte. An unauthenticated remote attacker who controls (or man-in-the-middles) a Git server reached over HTTP/HTTPS/SSH/git:// can trigger this on the FIRST ref-pkt of the refs advertisement, before any capability negotiation has taken place. The OOB walk causes a process crash (SIGSEGV) when memchr enters an unmapped page, and -- on heap layouts where memchr finds a stray space byte before crashing -- can additionally drive the git_error_set(\u0022...\u0027%.*s\u0027\u0022, format_len, format_str) formatter to copy a large window of heap memory into the error string.\n\nCVE-2026-15957:\n\tSmithy-RS is a Rust code generation and runtime framework that generates HTTP clients and servers from Smithy interface definitions, powering the AWS SDK for Rust and custom service implementations.\n\n\n\nUncontrolled recursion in the JSON, CBOR, and XML deserializer functions emitted by Amazon smithy-rs code generation could allow remote attackers to cause a denial of service (process abort via stack exhaustion) via a small request containing deeply nested data for a recursive model shape to a generated SDK or server.\n\n\n\nTo mitigate this issue, users should upgrade to aws-sdk-rust release-2026-06-02 or later. Users building custom servers with smithy-rs codegen should regenerate from smithy-rs release-2026-06-01 or later.",
  "published": "2026-09-28T09:00:00Z",
  "severity": "important",
  "epss": 0.00412,
  "epssPercentile": 0.35756,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "amazon-efs-utils",
      "release": "amzn 2023",
      "fixedVersion": "3.1.3-1.amzn2023",
      "fix": "ALAS2023-2026-3333",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3333",
      "released": "2026-11-07T01:06:07Z"
    },
    {
      "platform": "linux",
      "product": "network-flow-monitor-agent",
      "release": "amzn 2023",
      "fixedVersion": "1.1.8-1.amzn2023.0.1",
      "fix": "ALAS2023-2026-3116",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3116",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "network-flow-monitor-agent-debuginfo",
      "release": "amzn 2023",
      "fixedVersion": "1.1.8-1.amzn2023.0.1",
      "fix": "ALAS2023-2026-3116",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3116",
      "released": "2026-09-28T09:00:00Z"
    },
    {
      "platform": "linux",
      "product": "network-flow-monitor-agent-debugsource",
      "release": "amzn 2023",
      "fixedVersion": "1.1.8-1.amzn2023.0.1",
      "fix": "ALAS2023-2026-3116",
      "url": "https://patchblox.com/security/fix/linux/alas2023-2026-3116",
      "released": "2026-09-28T09:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}