CVE-2026-67216

cJSON cJSON_Compare Exponential Complexity Denial of Service

cJSON through 1.7.19 contains an inefficient algorithmic complexity flaw in cJSON_Compare(). When comparing objects, the function recurses into each shared subtree twice, once in each direction, with no depth guard, making the running time exponential in nesting depth. A small, deeply nested document of a few hundred bytes (depth around 40) compared for equality consumes hours of CPU, and the cost roughly doubles with each additional level of nesting. An application that calls cJSON_Compare() on attacker-influenced JSON that is structurally equal to a reference document is exposed to a denial-of-service condition.

CVSS 4.0 · 8.2 High EPSS < 1% KEV · Not listed

Vendors

Davegamble

Products

Cjson

CVE-2026-64644

Next.js: Denial of Service in the Image Optimization API using SVGs

Next.js is a React framework for building full-stack web applications. In versions 15.5.0 through 15.5.20 and 16.0.0 through 16.2.10, when self-hosting Next.js with the default image loader, the Image Optimization API can optimize remotely hosted images if configured (not enabled by default). If those images contain malicious content, they can cause CPU exhaustion in /_next/image endpoints.Only config.images.remotePatterns is affected, and just the patterns in that array, whereas config.images.unoptimized: true, config.images.loader: 'custom', and Vercel are not impacted. This issue has been fixed in versions 15.5.21 and 16.2.11.

CVSS 4.0 · 6.3 Medium EPSS < 1% KEV · Not listed

Vendors

Vercel

Products

Next.js

CVE-2026-55685

React Router: Unauthenticated Denial of Service via Inefficient Route Matching

React Router is a router for React. In versions 7.0.0 through 7.17.0, the manifest endpoint could be accessed via unauthenticated targeted requests that would put heavy load on the server and slow down response times. This issue is a follow up to CVE-2026-42342, and does not does not impact React Router applications using Declarative Mode (<BrowserRouter>) or Data Mode (createBrowserRouter/<RouterProvider>). This issue has been fixed in version 7.18.0.

CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Vendors

Remix-run Shopify

Products

React-router React-router

CVE-2026-55968

Apache Thrift: Node.js quadratic-time DoS in server receive transports

Inefficient Algorithmic Complexity, Allocation of Resources Without Limits or Throttling vulnerability in Apache Thrift Node.js bindings. This issue affects Apache Thrift: before 0.24.0. Users are recommended to upgrade to version 0.24.0, which fixes the issue.

CVSS 4.0 · 8.7 High EPSS 1.0% KEV · Not listed

Vendors

Apache

Products

Thrift

CVE-2026-65623

Quadratic CPU blow-up reassembling fragmented WebSocket messages in Bandit

Inefficient Algorithmic Complexity vulnerability in mtrudel bandit allows unauthenticated remote denial of service via CPU exhaustion during WebSocket fragment reassembly. The size guard 'Elixir.Bandit.WebSocket.Connection':oversize_message?/2 called from handle_frame/3 in lib/bandit/websocket/connection.ex appends each non-final continuation frame to a left-nested iolist and then re-measures the entire accumulated buffer with IO.iodata_length/1 on every frame. Because the buffer grows by one element per frame and is fully re-traversed each time, reassembly work is quadratic (O(n^2)) in the number of continuation frames. The max_fragmented_message_size limit (default 8 MB) bounds total bytes but not frame count, and each frame can carry as little as one payload byte, so an attacker can send millions of tiny continuation frames using modest bandwidth to pin a CPU core for minutes to hours. Many concurrent connections can starve the whole server of CPU, denying service to legitimate users. The WebSocket read timeout does not help, because it is an idle timeout evaluated between reads and cannot preempt the synchronous reassembly work spent inside a single callback. This issue affects bandit: from 1.11.0 before 1.12.1.

CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Vendors

Mtrudel

Products

Bandit

CVE-2026-13064

MongoDB $jsonSchema Query Operator Excessive CPU Consumption Leading to Denial of Service

Certain query operations involving deeply nested $jsonSchema constructs can trigger disproportionate CPU consumption in affected MongoDB deployments, potentially leading to resource exhaustion. The resulting CPU-bound operation cannot be interrupted through standard administrative controls.

CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed

Vendors

Mongodb

Products

Mongodb Mongodb Server

CVE-2026-8594

Text::LineFold versions through 2019.001 for Perl duplicate the output based on the number of special break characters

Text::LineFold versions through 2019.001 for Perl duplicate the output based on the number of special break characters. Text::LineFold splits the input string by specific line break characters (such as VT, FF and others) into segments, but applies the break function to the entire string, not just the segment. A side effect of this is that the full input can be duplicated for each segment. Besides being incorrect, this can lead to unexpected resource consumption and possible denial of service. Note that Text::LineFold is part of the Unicode-LineBreak distribution, which may have a higher version number than the module.

CVSS 3.1 · 6.2 Medium EPSS < 1% KEV · Not listed

Vendors

Nezumi

Products

Text::linefold

CVE-2026-59885

pyasn1: Quadratic complexity in OBJECT IDENTIFIER and RELATIVE-OID processing allows denial of service

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER, CER, and DER decoders process OBJECT IDENTIFIER and RELATIVE-OID values in quadratic time relative to the number of arcs, so a small crafted payload containing an OID with many arcs consumes excessive CPU per decode() call and can deny service to applications that decode untrusted ASN.1 data. The corresponding encoders have the same quadratic behavior when an application re-encodes previously decoded attacker-supplied values. This issue is fixed in version 0.6.4.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Pyasn1

Products

Pyasn1

CVE-2026-59869

js-yaml: YAML merge-key chains can force quadratic CPU consumption

js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chain of mappings uses merge keys where each mapping merges the previous one. This issue is fixed in versions 3.15.0 and 4.3.0.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Nodeca Redhat

Products

Js-yaml Hummingbird

CVE-2026-56669

Elysia: Inefficient Algorithmic Complexity and Interpretation Conflict

Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation, and client-server communication. Prior to 1.4.29, Elysia uses getAll in form data normalization for multipart/form-data endpoints, causing the amount of work to grow quadratically with the number of unique key-value pairs and allowing CPU exhaustion. This issue is fixed in version 1.4.29.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Elysiajs

Products

Elysia

CVE-2026-59928

Mistune block_parser: quadratic-time parsing on long lists of repeated reference-link definitions

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a Markdown document containing many repeated or distinct reference-link definitions causes quadratic work in src/mistune/block_parser.py and the ref_links environment dictionary handling, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Lepture Mistune Project

Products

Mistune Mistune

CVE-2026-59922

Mistune plugins/formatting: quadratic-time parsing on long runs of `~~x~~`, `==x==`, and `^^x^^` markers (strikethrough / mark / insert)

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugins/formatting.py when the strikethrough, mark, or insert plugin scans for matching markers from each possible start position, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Lepture Mistune Project

Products

Mistune Mistune

CVE-2026-55206

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

py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and decryption. Prior to 1.1.3, PackInfo._read() in archiveinfo.py used an O(n^2) cumulative sum pattern for attacker-controlled numstreams values parsed from archive headers, allowing a crafted .7z archive to cause excessive CPU consumption during SevenZipFile.init() before extraction. This issue is fixed in version 1.1.3.

CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Vendors

Miurahr

Products

Py7zr

CVE-2026-57480

Parse Server: Denial of service via exponential-time processing of deeply nested query operators

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.9.1-alpha.12 and 8.6.82, deeply nested $or, $and, and $nor query condition operators in the REST API or LiveQuery query handling could trigger exponential-time processing in the internal query-traversal helper and block the Node.js event loop. This issue is fixed in versions 9.9.1-alpha.12 and 8.6.82.

CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Vendors

Parse Community

Products

Parse Server

CVE-2026-59868

js-yaml: YAML merge-key chains can force quadratic CPU consumption

js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.0, when merge keys are enabled, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chain of mappings uses merge keys where each mapping merges the previous one. This issue is fixed in version 5.2.0.

CVSS 3.1 · 5.3 Medium EPSS < 1% KEV · Not listed

Vendors

Nodeca Redhat

Products

Js-yaml Hummingbird

CVE-2026-59925

inline_parser: quadratic-time parsing on long runs of `**x**` and `***x***` emphasis pairs

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, long sequences of well-formed double-asterisk or triple-asterisk emphasis pairs around a character cause quadratic work in src/mistune/inline_parser.py because the parser scans forward for matching close markers from every potential opening run, allowing denial of service in default Mistune parsing. This issue is fixed in version 3.3.0.

CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed

Vendors

Lepture Mistune Project

Products

Mistune Mistune

CVE-2026-59880

Immutable.js: Hash-collision algorithmic complexity denial of service in Immutable.Map/Set

Immutable.js provides many Persistent Immutable data structures. Prior to 4.3.9 and 5.1.8, Immutable.Map and Immutable.Set keep keys that share the same 32-bit hash in a HashCollisionNode collision bucket that is scanned linearly, allowing an attacker who controls keys inserted into a Map, such as through Immutable.Map(obj), Immutable.fromJS(obj), state.merge(userObject), or mergeDeep, to craft many colliding keys and degrade insertion and lookup to consume disproportionate CPU. This issue is fixed in versions 4.3.9 and 5.1.8.

CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Vendors

Immutable-js

Products

Immutable Immutable-js

CVE-2026-59094

Pathway - Unauthenticated Denial of Service via Exponential Glob Pattern Matching in Document Store

Pathway through 0.31.1, fixed in commit d09722e, document store applies a caller-supplied glob pattern to indexed document paths using a hand-written recursive matcher that branches two ways on each ** token without memoization, giving exponential worst-case complexity. The filepath_globpattern value is taken from the body of the unauthenticated HTTP endpoints /v1/retrieve, /v1/inputs and /v2/answer and compiled into a filter evaluated once per indexed document, with no length or **-count limit. A remote unauthenticated attacker can submit a short pattern containing many ** tokens to consume CPU for tens of seconds per request, and a small number of requests denies service.

CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Vendors

Pathwaycom

Products

Pathway

CVE-2026-58226

Unauthenticated denial-of-service via unbounded HPACK integer decoding in hpax

Inefficient Algorithmic Complexity vulnerability in elixir-mint hpax allows unauthenticated denial-of-service via unbounded HPACK integer decoding. hpax decodes HPACK variable-length integers with no upper bound on the decoded value or the number of continuation octets. 'Elixir.HPAX.Types':decode_remaining_integer/3 accumulates the integer as int + (value <<< m), shifting by 7 more bits for each continuation octet and stopping only on a terminating octet or truncated input, never because the integer grew too large. Because BEAM integers are arbitrary precision, a run of N continuation octets builds an O(N)-bit bignum and re-adds into an ever-larger bignum on each step, so the total decoding cost is superlinear (about O(N^2)). An unauthenticated attacker who can send an HTTP/2 header block to a server using this decoder (reached through the 'Elixir.HPAX':decode/2 entry point) can supply a small header block that forces a large, attacker-controlled amount of CPU (and transient memory), a denial-of-service amplification. This issue affects hpax from 0.1.1 before 1.0.4.

CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed

Vendors

Elixir-mint

Products

Hpax

CVE-2026-45822

decode-uri-component: decode-uri-component: Denial of Service via crafted input

decode-uri-component through 0.4.1 is vulnerable to denial of service. The decode() function splits input on '%' producing N tokens and calls decodeComponents(), exhibiting super-linear parsing time: 200 '%ab' tokens takes approximately 0.7s, 700 tokens approximately 6s, and 1400 tokens approximately 33s. An attacker can cause significant CPU consumption and event-loop blocking via crafted input.

CVSS 4.0 · 6.6 Medium EPSS < 1% KEV · Not listed

Vendors

Samverschueren

Products

Decode-uri-component