PT-2026-56519

Name of the Vulnerable Software and Affected Versions Mistune versions prior to 3.3.0 Description A Python Markdown parser with renderers and plugins contains an issue where a Markdown document with numerous repeated or distinct reference-link definitions triggers quadratic work within...

PYSEC-2026-1975 Tornado has an HTTP cookie parsing DoS vulnerability

The algorithm used for parsing HTTP cookies in Tornado versions prior to 6.4.2 sometimes has quadratic complexity, leading to excessive CPU consumption when parsing maliciously-crafted cookie headers. This parsing occurs in the event loop thread and may block the processing of other requests. See...

Regular Expression Denial of Service (ReDoS)

Overview linkify-it is a Links recognition library with FULL unicode support Affected versions of this package are vulnerable to Regular Expression Denial of Service ReDoS due to quadratic algorithmic complexity in the match function. An attacker can exhaust CPU resources and cause significant...

LinkifyIt#match scan loop has quadratic algorithmic complexity

Summary LinkifyIt.prototype.match — the package's primary public API — has ON² algorithmic complexity for inputs containing many fuzzy links or emails. This is not a regex backtrack bug; it's a structural issue in the JS-level scan loop that re-slices the input and re-runs unanchored regex search...

NPM: LinkifyIt#match scan loop has quadratic algorithmic complexity

NPM: LinkifyItmatch scan loop has quadratic algorithmic complexity vulnerability discovered by ? in WordPress Npm linkify-it versions = 5.0.0...

PT-2026-53018

Name of the Vulnerable Software and Affected Versions linkify-it versions prior to 5.0.1 Description LinkifyIt.prototype.match, the primary public API of the library, exhibits ON² algorithmic complexity when processing inputs containing numerous fuzzy links or emails. This occurs because the...

Inefficient Algorithmic Complexity

Overview org.webjars.npm:shell-quote is a package used to quote and parse shell commands. Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity in the parseInternal function of parse.js, where parse finalizes the token list with Array.prototype.concat inside a...

CVE-2026-48511 MessagePack-CSharp: ExpandoObject formatter can perform quadratic insertion work on untrusted maps

MessagePack for C is a MessagePack serializer for C. Prior to 2.5.301 and 3.1.7, ExpandoObjectFormatter.Deserialize populates System.Dynamic.ExpandoObject by calling IDictionary.Add for each map entry. ExpandoObject internally maintains member names in array-like structures, so inserting many...

CVE-2026-48511 MessagePack-CSharp: ExpandoObject formatter can perform quadratic insertion work on untrusted maps

MessagePack for C is a MessagePack serializer for C. Prior to 2.5.301 and 3.1.7, ExpandoObjectFormatter.Deserialize populates System.Dynamic.ExpandoObject by calling IDictionary.Add for each map entry. ExpandoObject internally maintains member names in array-like structures, so inserting many...

CVE-2026-53539

Python-Multipart is a streaming multipart parser for Python. Prior to 0.0.30, when parsing application/x-www-form-urlencoded bodies, QuerystringParser located the field separator with a two step lookup: it first scanned the entire remaining buffer for &, and only when no & existed anywhere ahead...

CVE-2026-53550 js-yaml: Quadratic-complexity DoS in merge key handling via repeated aliases

js-yaml is a JavaScript YAML parser and dumper. Prior to 4.2.0 and 3.15.0, a crafted YAML document can trigger algorithmic CPU exhaustion in js-yaml merge-key processing by repeating the same alias many times in a merge sequence. This causes quadratic parse-time behavior relative to input size an...

CVE-2026-53550 js-yaml: Quadratic-complexity DoS in merge key handling via repeated aliases

js-yaml is a JavaScript YAML parser and dumper. Prior to 4.2.0 and 3.15.0, a crafted YAML document can trigger algorithmic CPU exhaustion in js-yaml merge-key processing by repeating the same alias many times in a merge sequence. This causes quadratic parse-time behavior relative to input size an...

CVE-2026-53550

js-yaml vulnerability CVE-2026-53550 stems from the merge-key handling (<<) in lib/loader.js, causing quadratic parse-time DoS when processing crafted YAML with repeated aliases prior to version 4.2.0. Affected: js-yaml

GHSA-H4GH-22QQ-72R7 py7zr: O(n^2) algorithmic complexity DoS in PackInfo._read()

Summary PackInfo.read uses an On^2 cumulative sum pattern where numstreams is read directly from the archive header. A crafted .7z archive with a large numstreams value causes excessive CPU consumption during SevenZipFile.init — no extraction is needed. A 50 KB archive takes 7 seconds of CPU time...

py7zr: O(n^2) algorithmic complexity DoS in PackInfo._read()

Summary PackInfo.read uses an On^2 cumulative sum pattern where numstreams is read directly from the archive header. A crafted .7z archive with a large numstreams value causes excessive CPU consumption during SevenZipFile.init — no extraction is needed. A 50 KB archive takes 7 seconds of CPU time...

CVE-2026-49293 CPU exhaustion via O(n^2) BigInt construction on radix-prefixed integer literals

js-toml is a TOML parser for JavaScript, fully compliant with the TOML 1.0.0 Spec. Versions up to and including 1.1.0 parse hexadecimal / octal / binary integer literals via a hand-written parseBigInt loop that multiplies a BigInt accumulator by the radix once per input digit. Each iteration...

CVE-2026-49293 CPU exhaustion via O(n^2) BigInt construction on radix-prefixed integer literals

js-toml is a TOML parser for JavaScript, fully compliant with the TOML 1.0.0 Spec. Versions up to and including 1.1.0 parse hexadecimal / octal / binary integer literals via a hand-written parseBigInt loop that multiplies a BigInt accumulator by the radix once per input digit. Each iteration...

PT-2026-51098

Name of the Vulnerable Software and Affected Versions py7zr versions prior to 1.1.3 Description A denial of service issue exists where a crafted .7z archive with a large numstreams value causes excessive CPU consumption. This occurs because the PackInfo. read function in archiveinfo.py uses an On...

markdown-it: Quadratic complexity DoS in smartquotes rule via replaceAt string operations

Summary A quadratic time complexity vulnerability exists in markdown-it's smartquotes rule enabled via the typographer: true option. An attacker can craft a markdown input consisting of consecutive quotation marks that causes the parser to consume excessive CPU time, leading to denial of service...

NPM: JS-YAML: Quadratic-complexity DoS in merge key handling via repeated aliases

NPM: JS-YAML: Quadratic-complexity DoS in merge key handling via repeated aliases vulnerability discovered by ? in WordPress Npm js-yaml versions = 4.1.1...