UnratedFix available

DEBIAN-CVE-2026-86818

Type: advisorySource: OSV1 source record

fast-uri is a dependency-free RFC 3986 URI parser for Node.js, used by Fastify and ajv, that added a mailto scheme parser in version 4.1.3. In versions 4.1.3 and 4.1.4, the mailto parser compares each query field name to the reserved names to, subject, and body while the name is still percent-encoded, and decodes it only when storing it as a generic header, so a percent-encoded spelling of a reserved field name is not recognized as that field at parse time but is re-emitted as the literal field name when the parsed URI is serialized. An application that validates, logs, or displays the recipient list from the first parse and then serializes the URI and sends it can silently gain an attacker-chosen recipient, and the subject and body fields can be smuggled across the same roundtrip. The issue is fixed in fast-uri 4.1.5, and users should upgrade to 4.1.5 or later. As a workaround, do not act on a mailto URI that fast-uri has re-serialized without first decoding and re-validating its recipient, subject, and body fields.

Announced 15 Sept 2026Group revision 1

Original source ↗

DEBIAN-CVE-2026-86818

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:DEBIAN-CVE-2026-86818

node-ajv

Source reference: /affected/0/package/name

Affected versions: 8.12.0~ds+~2.1.1-5
Source reference: /affected/0/versions
8.17.1~ds+~3.0.1+~3.1.0-1
Source reference: /affected/0/versions
8.17.1~ds+~3.0.1+~3.1.0-2
Source reference: /affected/0/versions
8.17.1~ds+~3.0.1+~3.1.0-3
Source reference: /affected/0/versions
8.17.1~ds+~3.0.1+~3.1.0-4
Source reference: /affected/0/versions
8.18.0~ds+~cs6.1.1-1
Source reference: /affected/0/versions
8.18.0~ds+~cs6.1.1-2
Source reference: /affected/0/versions
8.20.0~ds+~cs6.1.3-1
Source reference: /affected/0/versions
8.20.0~ds+~cs7.1.2-1
Source reference: /affected/0/versions
8.20.0~ds+~cs7.1.3-1
Source reference: /affected/0/versions
8.20.0~ds+~cs7.1.3-2
Source reference: /affected/0/versions
8.20.0~ds+~cs7.1.3-3
Source reference: /affected/0/versions
8.20.0~ds+~cs7.1.4-1
Source reference: /affected/0/versions
8.20.0~ds+~cs7.1.5-1
Source reference: /affected/0/versions
8.20.0~ds+~cs7.1.6-1
Source reference: /affected/0/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

node-ajv

Source reference: /affected/1/package/name

Affected versions: 8.12.0~ds+~2.1.1-5
Source reference: /affected/1/versions
8.17.1~ds+~3.0.1+~3.1.0-1
Source reference: /affected/1/versions
8.17.1~ds+~3.0.1+~3.1.0-2
Source reference: /affected/1/versions
8.17.1~ds+~3.0.1+~3.1.0-3
Source reference: /affected/1/versions
8.17.1~ds+~3.0.1+~3.1.0-4
Source reference: /affected/1/versions
8.18.0~ds+~cs6.1.1-1
Source reference: /affected/1/versions
8.18.0~ds+~cs6.1.1-2
Source reference: /affected/1/versions
8.20.0~ds+~cs6.1.3-1
Source reference: /affected/1/versions
8.20.0~ds+~cs7.1.2-1
Source reference: /affected/1/versions
8.20.0~ds+~cs7.1.3-1
Source reference: /affected/1/versions
8.20.0~ds+~cs7.1.3-2
Source reference: /affected/1/versions
8.20.0~ds+~cs7.1.3-3
Source reference: /affected/1/versions
8.20.0~ds+~cs7.1.4-1
Source reference: /affected/1/versions
8.20.0~ds+~cs7.1.5-1
Source reference: /affected/1/versions
Fixed versions: 8.20.0~ds+~cs7.1.6-1
Source reference: /affected/1/ranges
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "node-ajv",
      "purl": "pkg:deb/debian/node-ajv?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "8.12.0~ds+~2.1.1-5",
      "8.17.1~ds+~3.0.1+~3.1.0-1",
      "8.17.1~ds+~3.0.1+~3.1.0-2",
      "8.17.1~ds+~3.0.1+~3.1.0-3",
      "8.17.1~ds+~3.0.1+~3.1.0-4",
      "8.18.0~ds+~cs6.1.1-1",
      "8.18.0~ds+~cs6.1.1-2",
      "8.20.0~ds+~cs6.1.3-1",
      "8.20.0~ds+~cs7.1.2-1",
      "8.20.0~ds+~cs7.1.3-1",
      "8.20.0~ds+~cs7.1.3-2",
      "8.20.0~ds+~cs7.1.3-3",
      "8.20.0~ds+~cs7.1.4-1",
      "8.20.0~ds+~cs7.1.5-1",
      "8.20.0~ds+~cs7.1.6-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-86818.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "8.20.0~ds+~cs7.1.6-1"
          }
        ]
      }
    ],
    "package": {
      "name": "node-ajv",
      "purl": "pkg:deb/debian/node-ajv?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "8.12.0~ds+~2.1.1-5",
      "8.17.1~ds+~3.0.1+~3.1.0-1",
      "8.17.1~ds+~3.0.1+~3.1.0-2",
      "8.17.1~ds+~3.0.1+~3.1.0-3",
      "8.17.1~ds+~3.0.1+~3.1.0-4",
      "8.18.0~ds+~cs6.1.1-1",
      "8.18.0~ds+~cs6.1.1-2",
      "8.20.0~ds+~cs6.1.3-1",
      "8.20.0~ds+~cs7.1.2-1",
      "8.20.0~ds+~cs7.1.3-1",
      "8.20.0~ds+~cs7.1.3-2",
      "8.20.0~ds+~cs7.1.3-3",
      "8.20.0~ds+~cs7.1.4-1",
      "8.20.0~ds+~cs7.1.5-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-86818.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event: #58219 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 17:46:22 GMT
Publisher date: Tue, 15 Sep 2026 11:17:12 GMT

Read the original announcement

Revision history

25 Oct 2026DEBIAN-CVE-2026-86818 · Revision 1Source updated