CVE-2026-54080: Parser Denial of Service Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-jrmc-qg6p-94fp",
  "modified" : "2026-07-29T15:17:32Z",
  "published" : "2026-07-29T15:17:32Z",
  "aliases" : [ "CVE-2026-54080" ],
  "summary" : "veraPDF Parser DoS via PostScript CMap Streams",
  "details" : "## Summary\n\n**Description**\n\nA PostScript-interpreter-driven Denial of Service (CWE-1325) vulnerability in veraPDF allows a remote attacker to exhaust validator memory or CPU by submitting a PDF whose Type 0 font `/Encoding` (or any `/ToUnicode`) is a CMap stream containing attacker-supplied PostScript. veraPDF reuses its CMap parser as a general PostScript interpreter and exposes the unguarded `array N` allocation operator and the `for` control operator with no zero-increment guard. This affects all current versions of veraPDF-parser.\n\n## Details\n\nThe vulnerability resides in veraPDF-parser. CMap streams referenced as a Type 0 font's `/Encoding` (or any font's `/ToUnicode`) are parsed by `CMapParser` (veraPDF-parser/src/main/java/org/verapdf/pd/font/cmap/CMapParser.java), which extends `PSParser`. Tokens that are not the small CMap-specific keyword set (`begincodespacerange`, `bfchar`, `cidchar`, ...) fall through to `PSObject.execute` (veraPDF-parser/src/main/java/org/verapdf/parser/postscript/PSObject.java), which dispatches generic PostScript operators implemented in `PSOperator` (veraPDF-parser/src/main/java/org/verapdf/parser/postscript/PSOperator.java).\n\nTwo operators in that interpreter take their bound from the PDF and apply no validation:\n1. `array` at PSOperator.java:536-547 pops the top number from the operand stack and immediately calls `COSArray.construct(arraySize)`, then loops `arraySize` times appending `COSObject.getEmpty()`. `COSArray.construct(int)` calls `new ArrayList<>(arraySize)` (COSArray.java:102), so the underlying `Object[]` is allocated up-front. Passing `2147483647` (`Integer.MAX_VALUE`) requests a 16 GB backing array on a 64-bit JVM.\n2. `for` at PSOperator.java:571-592 reads `initial`, `increment`, and `limit` from the stack and loops `for (long i = initial; i <= limit; i += increment)`. Because `increment` is unchecked, `0 0 1 { } for` produces an infinite-CPU spin (and progressively a heap exhaustion as each iteration pushes `i` onto the operand stack).\n\n`CMapFactory.getCMap` only catches `IOException` and `PostScriptException`; it does not catch `OutOfMemoryError` or wall-clock budget, so the failure propagates out of font model construction and aborts the validation worker.\n\nA single payload byte sequence, the unframed PostScript `2147483647 array`, is sufficient. No `begincmap`/`endcmap` framing is required because the operator runs before the parser ever reaches the CMap structure.\n\n## Impact\n\nThis impacts all current releases of the veraPDF-parser. Successful exploitation requires only that the target validate an attacker-supplied PDF; a single Type 0 font with a malicious `/Encoding` (or any `/ToUnicode`) stream is sufficient.\n\n## Proposed Patch\n\nCap `array` allocation and forbid zero increments in `for`.\n\nAs a defensive measure, also wrap `CMapFactory.getCMap` to enforce a wall-clock and operand-stack-size budget on CMap parsing, and audit the remaining unbounded operators (`copy`, `roll`, `dict`) for similar primitives.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.verapdf:parser"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.30.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.30.1"
    }
  }, {
    "package" : {
      "ecosystem" : "Maven",
      "name" : "org.verapdf:parser"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.31.1"
      }, {
        "fixed" : "1.31.23"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.31.22"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/veraPDF/veraPDF-parser/security/advisories/GHSA-jrmc-qg6p-94fp"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/veraPDF/veraPDF-parser/pull/703"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/veraPDF/veraPDF-parser/commit/73d6ec002b98ce1f3f68640442f8e5d5613c80ce"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/veraPDF/veraPDF-parser/commit/cb3538607a549d63504299be1088c85ae48605f4"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/veraPDF/veraPDF-parser"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1325" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-07-29T15:17:32Z",
    "nvd_published_at" : null
  }
}