CVE-2026-83619

xmldom: End-tag Whitespace-Trim Regex ReDoS — quadratic backtracking in the 0.8.x end-tag parser

xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.7.0 until 0.8.15, the release-0.8.x parser in lib/sax.js trims captured end-tag names with the unanchored global expression /[ \t\n\r]+$/g. For an end tag containing a long whitespace run followed by a non-whitespace character, the expression retries from each possible starting position and backtracks quadratically before failing its end anchor. DOMParser.parseFromString() reaches the path under default options, allowing a small unauthenticated XML input to stall the Node.js event loop; the 0.9.x and unscoped npm lines do not contain this expression. This issue is fixed in @xmldom/xmldom version 0.8.15.

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

Vendors

Xmldom

Products

Xmldom

CVE-2026-83606

xmldom PI grammar regex ReDoS: quadratic backtracking on unterminated processing instructions

xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.0-beta.9 until 0.9.11, the processing-instruction production in lib/grammar.js lets the greedy S+ separator and lazy Char*? data group repeatedly repartition a long whitespace tail when the required closing ?> is absent. Both parsePI and parseProcessingInstruction apply the expression to the entire remaining source, causing quadratic backtracking during DOMParser.parseFromString() under default options and allowing a small unauthenticated XML input to stall the Node.js event loop. This issue is fixed in @xmldom/xmldom version 0.9.11.

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

Vendors

Xmldom

Products

Xmldom

CVE-2026-79770

Nokogiri before 1.19.3 ReDoS via CSS selector tokenizer

Nokogiri versions before 1.19.3 contain regular expression denial of service vulnerabilities in the CSS selector tokenizer affecting string-literal and identifier tokenization. Attackers can inject adversarial CSS selectors into methods like Node#css, Node#at_css, and Searchable#search to cause exponential regex backtracking and denial of service.

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

Vendors

Nokogiri

Products

Nokogiri

CVE-2026-81725

NLTK before 3.10.3 Regular Expression Denial of Service via Pl196xCorpusReader

NLTK before 3.10.3 contains a regular expression denial of service vulnerability in Pl196xCorpusReader that allows attackers to cause quadratic CPU consumption by supplying malformed TEI blocks with many unmatched opening tags. Attackers can exploit lazy regex patterns in the read_block method through public APIs like words() and tagged_words() to force repeated rescans and achieve near-quadratic runtime growth.

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

Vendors

Nltk

Products

Nltk

CVE-2026-55520

Protego: Exponential backtracking ReDoS in robots.txt URL wildcard matching

Protego is a pure-Python robots.txt parser with support for modern conventions. Prior to 0.6.2, protego._urlpattern._URLPattern._prepare_pattern_for_regex translates every asterisk in an Allow or Disallow directive into a lazy regular-expression wildcard, so a directive containing many asterisks creates exponential backtracking. After protego.Protego.parse processes a crafted robots.txt file, protego.Protego.can_fetch can spend an attacker-controlled period matching a near-miss URL and deny service to the crawler. The vulnerable path is src/protego/_urlpattern.py in the _URLPattern match logic. This issue is fixed in version 0.6.2.

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

Vendors

Scrapy

Products

Protego

CVE-2024-58379

nodemailer before 6.9.9 ReDoS via attachDataUrls parameter

nodemailer before 6.9.9 contains a regular expression denial of service vulnerability in email parsing when attachDataUrls parameter is set or processing embedded file attachments. Attackers can send specially crafted emails with malicious data URLs or embedded attachments to cause the event loop to hang and deny service.

CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed

Vendors

Nodemailer

Products

Nodemailer

CVE-2026-66766

Denial of Service (DoS) in SAP S/4HANA (Manage Supply Protection)

SAP S/4HANA (Private Cloud) uses a third-party component that contains a Regular Expression Denial of Service (ReDoS) vulnerability. An unauthenticated attacker could supply specially crafted input that triggers excessive processing within the affected functionality. Successful exploitation could exhaust system resources and make the service unavailable, resulting in a high impact on availability. There is no impact on confidentiality and integrity.

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

Vendors

Sap Se

Products

Sap S/4hana (manage Supply Protection)

CVE-2026-49851

Mistune: Potential DoS via quadratic-time parsing in parse_link_text

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, Mistune is vulnerable to a CPU exhaustion DoS due to superlinear (approximately O(n²)) behavior in parse_link_text. When parsing Markdown containing many consecutive [ characters, parse_link_text repeatedly scans the input using a regex search inside a loop. Each iteration re-scans a large portion of the remaining string, resulting in quadratic-time behavior. An attacker-controlled Markdown input can therefore trigger excessive CPU usage with a very small payload. This vulnerability is fixed in 3.3.0.

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

Vendors

Lepture

Products

Mistune

CVE-2026-33079

Mistune ReDoS in LINK_TITLE_RE allows denial of service with crafted Markdown titles

In versions 3.0.0a1 through 3.2.0 of Mistune, there is a ReDoS (Regular Expression Denial of Service) vulnerability in `LINK_TITLE_RE` that allows an attacker who can supply Markdown for parsing to cause denial of service. The regular expression used for parsing link titles contains overlapping alternatives that can trigger catastrophic backtracking. In both the double-quoted and single-quoted branches, a backslash followed by punctuation can be matched either as an escaped punctuation sequence or as two ordinary characters, creating an ambiguous pattern inside a repeated group. If an attacker supplies Markdown containing repeated ! sequences with no closing quote, the regex engine explores an exponential number of backtracking paths. This is reachable through normal Markdown parsing of inline links and block link reference definitions. A small crafted input can therefore cause significant CPU consumption and make applications using Mistune unresponsive.

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

Vendors

Lepture

Products

Mistune

CVE-2026-58436

ParseAcceptLanguage quadratic-time DoS via Locale middleware on unauthenticated requests

ParseAcceptLanguage quadratic-time DoS via Locale middleware on unauthenticated requests

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

Vendors

Gitea

Products

Gitea Open Source Git Server

CVE-2026-80206

NLTK 3.10.2 Regular Expression Denial of Service via tgrep

NLTK before 3.10.3 contains a regular expression denial of service (ReDoS) vulnerability in the tgrep module. The _tgrep_node_action function compiles user-supplied regular expressions embedded in /regex/ pattern nodes and executes them via re.search against tree node labels without any validation or timeout. An attacker who controls the tgrep pattern (e.g., via tgrep_positions() or tgrep_compile() exposed to external input) can supply a pattern that triggers catastrophic backtracking, causing indefinite CPU saturation that blocks the Python process.

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

Vendors

Nltk

Products

Nltk

CVE-2026-70656

Checkmate: Regular Expression Denial of Service (ReDoS) via User-Controlled Regex in Monitor Advanced Matching

Checkmate is an open-source, self-hosted tool designed to track and monitor server hardware, uptime, response times, and incidents in real-time with beautiful visualizations. From 3.5.1 until 3.9.2, an authenticated admin or superadmin can set matchMethod to regex and place a malicious expression in the expectedValue field for advanced HTTP monitor matching. server/src/api/validation/monitorValidation.ts accepts the expression, and server/src/service/network/AdvancedMatcher.ts synchronously evaluates it against an attacker-controlled HTTP response body on the Node.js main event loop without a timeout or worker isolation, allowing catastrophic backtracking to freeze API endpoints, monitor checks, and WebSocket connections for all users. This issue is fixed in version 3.9.2.

CVSS 3.1 · 4.9 Medium EPSS < 1% KEV · Not listed

Vendors

Bluewave-labs

Products

Checkmate

CVE-2026-62317

Logto: ReDoS via unescaped user input in email subaddressing regex (blockSubaddressing)

Logto is the modern, open-source auth infrastructure for SaaS and AI apps. Prior to 1.41.0, Logto's email subaddressing blocklist in packages/core/src/libraries/sign-in-experience/email-blocklist-policy.ts used the attacker-controlled domain from email input to construct subaddressingRegex when blockSubaddressing was enabled. The permissive emailRegEx accepted multiple at signs and regular expression metacharacters, and POST /api/experience/verification/verification-code could therefore cause catastrophic backtracking in subaddressingRegex.test(email). The resulting event-loop stall could make authentication, token issuance, SSO, and the administrative console unavailable. This issue is fixed in version 1.41.0.

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

Vendors

Logto-io

Products

Logto

CVE-2026-59893

sqlparse: Inefficient Regex Handling of Dollar-Quoted SQL Literals Leads to ReDoS (Denial of Service)

sqlparse is a non-validating SQL parser module for Python. Prior to 0.6.0, SQL_REGEX in sqlparse/keywords.py and the per-position loop in sqlparse/lexer.py repeatedly scan unmatched dollar-quoted literal and multiline-comment delimiters, causing quadratic CPU consumption through sqlparse.parse(), sqlparse.format(), and sqlparse.split(). This issue is fixed in version 0.6.0.

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

Vendors

Andialbrecht

Products

Sqlparse

CVE-2026-54284

sqlparse: TokenList.__init__ materializes O(subtree) value per group, causing CPU DoS before depth/token caps trigger

sqlparse is a non-validating SQL parser module for Python. Prior to 0.6.0, TokenList construction and string conversion in sqlparse/sql.py repeatedly flatten nested token subtrees constructed by group_parenthesis and group_case, causing quadratic CPU consumption through sqlparse.parse(), sqlparse.format(), and sqlparse.split() before depth and token limits terminate processing. This issue is fixed in version 0.6.0.

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

Vendors

Andialbrecht

Products

Sqlparse

CVE-2026-72818

NLTK TweetTokenizer URL Pattern Backtracks Catastrophically on Naked-Domain-Like Input

The URLS regular expression in nltk/tokenize/casual.py, compiled into TweetTokenizer.WORD_RE and applied by TweetTokenizer.tokenize, contains a naked-domain branch whose domain-label prefix [a-z0-9]+(?:[.\-][a-z0-9]+)* is unbounded. Input consisting of many alternating label separators can be partitioned in exponentially many ways, and because the branch also requires a trailing top-level domain that such input never supplies, the engine explores those partitions before failing at each offset. A few kilobytes of input therefore consumes seconds to minutes of single-threaded CPU, and the HANG_RE substitution performed before matching does not collapse the pattern. TweetTokenizer is intended for tokenizing untrusted social-media text, so any service that applies it, or the module-level casual_tokenize, to submitted text can be stalled per request without authentication. Version 3.10.1 bounds the label repetition.

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

Vendors

Nltk

Products

Nltk

CVE-2026-62672

Grav: Authenticated ReDoS via regex_replace in Twig Sandbox

Grav is a file-based Web platform. Prior to 2.0.4, Grav allowlists the regex_replace filter and function in system/config/security.yaml, and GravExtension::regexReplace() passes an editor-controlled pattern directly to preg_replace(). When security.twig_content.process_enabled is enabled, an authenticated page editor can publish a catastrophically backtracking pattern that consumes PHP worker CPU and denies service to site visitors. This issue is fixed in version 2.0.4.

CVSS 4.0 · 6 Medium EPSS < 1% KEV · Not listed

Vendors

Getgrav

Products

Grav

CVE-2026-68749

Quadratic regex backtracking in the html_sanitize_ex CSS scrubber allows CPU-exhaustion denial of service

Inefficient Regular Expression Complexity vulnerability in the CSS scrubber in rrrene html_sanitize_ex allows an unauthenticated remote attacker to exhaust server CPU via a long CSS declaration in sanitized HTML. The declaration regex in HtmlSanitizeEx.Scrubber.CSS.scrub/1 matches the property name with an unbounded greedy [-\w]+ followed by a mandatory :, so a long run of word characters not followed by a colon makes the engine give back one character at a time and retry the colon at every start offset. The work is quadratic in the length of the run, and no length cap is applied to the CSS handed to the scrubber. An 80 KB <style> body costs roughly 2.4 seconds of scheduler time, so a few concurrent requests saturate the BEAM scheduler pool and make the application unresponsive. The impact is CPU exhaustion only. Nothing is read, modified or disclosed. This issue affects html_sanitize_ex: from 0.3.1 before 1.4.5 and from 1.5.0-rc.0 before 1.5.3.

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

Vendors

Rrrene

Products

Html Sanitize Ex Htmlsanitizeex

CVE-2026-72912

CyberChef’s pretty-recipe parser vulnerable to client-side ReDoS / CPU exhaustion when parsing a malformed #recipe= URL

CyberChef is a web app for encryption, encoding, compression, and data analysis. Prior to 11.3.0, CyberChef's pretty-recipe parser in src/core/Utils.mjs can exhaust client-side CPU when a malformed #recipe= URL fragment containing a large number of unmatched quote characters reaches Utils.parseRecipeConfig(). The function synchronously applies a complex global regular expression that may perform heavy backtracking before rejecting the input, causing the victim's browser tab to freeze during startup for seconds or longer. No code execution, data exfiltration, or privilege escalation occurs. This issue is fixed in version 11.3.0.

CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed

Vendors

Gchq

Products

Cyberchef

CVE-2026-47021

openjdk: OpenJDK: Enhance XBM image support (Oracle CPU 2026-07)

Vulnerability in the Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition product of Oracle Java SE (component: 2D). Supported versions that are affected are Oracle Java SE: 8u491, 8u491-perf, 11.0.31, 17.0.19, 21.0.11, 25.0.3, 26.0.1; Oracle GraalVM for JDK: 17.0.19 and 21.0.11; Oracle GraalVM Enterprise Edition: 21.3.18. Easily exploitable vulnerability allows unauthenticated attacker with network access via multiple protocols to compromise Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Successful attacks of this vulnerability can result in unauthorized ability to cause a partial denial of service (partial DOS) of Oracle Java SE, Oracle GraalVM for JDK, Oracle GraalVM Enterprise Edition. Note: This vulnerability can be exploited by using APIs in the specified Component, e.g., through a web service which supplies data to the APIs. This vulnerability also applies to Java deployments, typically in clients running sandboxed Java Web Start applications or sandboxed Java applets, that load and run untrusted code (e.g., code that comes from the internet) and rely on the Java sandbox for security. CVSS 3.1 Base Score 5.3 (Availability impacts). CVSS Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).

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

Vendors

Oracle

Products

Graalvm Graalvm Enterprise Edition Graalvm For Jdk and 3 more