Common Weakness Enumeration
CWE-1333
AllowedInefficient Regular Expression Complexity
Abstraction: Base · Status: Draft
The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.
824 vulnerabilities reference this CWE, most recent first.
CVE-2026-40319 (GCVE-0-2026-40319)
Vulnerability from cvelistv5 – Published: 2026-04-17 17:16 – Updated: 2026-04-20 13:46
VLAI
EPSS
VEX
Title
Giskard has a Regular Expression Denial of Service (ReDoS) in RegexMatching Check
Summary
Giskard is an open-source testing framework for AI models. In versions prior to 1.0.2b1, the RegexMatching check passes a user-supplied regular expression pattern directly to Python's re.search() without any timeout or complexity guard. A crafted regex pattern can trigger catastrophic backtracking, causing the process to hang indefinitely. Exploitation requires write access to a check definition and subsequent execution of the test suite. This issue has been fixed in giskard-checks version 1.0.2b1.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-20 13:43 UTC
CWE
- CWE-1333 - Inefficient Regular Expression Complexity
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/Giskard-AI/giskard-oss/securit… | x_refsource_CONFIRM |
| https://github.com/Giskard-AI/giskard-oss/release… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| Giskard-AI | giskard-oss |
Affected:
< 1.0.2b1
|
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CVE-2026-39320 (GCVE-0-2026-39320)
Vulnerability from cvelistv5 – Published: 2026-04-21 00:07 – Updated: 2026-04-21 19:36
VLAI
EPSS
VEX
Title
Signal K Server has an Unauthenticated Regular Expression Denial of Service (ReDoS) via WebSocket Subscription Paths
Summary
Signal K Server is a server application that runs on a central hub in a boat. Versions prior to 2.25.0 are vulnerable to an unauthenticated Regular Expression Denial of Service (ReDoS) attack within the WebSocket subscription handling logic. By injecting unescaped regex metacharacters into the `context` parameter of a stream subscription, an attacker can force the server's Node.js event loop into a catastrophic backtracking loop when evaluating long string identifiers (like the server's self UUID). This results in a total Denial of Service (DoS) where the server CPU spikes to 100% and becomes completely unresponsive to further API or socket requests. Version 2.25.0 contains a fix.
Severity
7.5 (High)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-21 19:36 UTC
CWE
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/SignalK/signalk-server/securit… | x_refsource_CONFIRM |
| https://github.com/SignalK/signalk-server/pull/2568 | x_refsource_MISC |
| https://github.com/SignalK/signalk-server/commit/… | x_refsource_MISC |
| https://github.com/SignalK/signalk-server/release… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| SignalK | signalk-server |
Affected:
< 2.25.0
|
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CVE-2026-35611 (GCVE-0-2026-35611)
Vulnerability from cvelistv5 – Published: 2026-04-07 16:38 – Updated: 2026-04-09 14:36
VLAI
EPSS
VEX
Title
Addressable has a Regular Expression Denial of Service in Addressable templates
Summary
Addressable is an alternative implementation to the URI implementation that is part of Ruby's standard library. From 2.3.0 to before 2.9.0, within the URI template implementation in Addressable, two classes of URI template generate regular expressions vulnerable to catastrophic backtracking. Templates using the * (explode) modifier with any expansion operator (e.g., {foo*}, {+var*}, {#var*}, {/var*}, {.var*}, {;var*}, {?var*}, {&var*}) generate patterns with nested unbounded quantifiers that are O(2^n) when matched against a maliciously crafted URI. Templates using multiple variables with the + or # operators (e.g., {+v1,v2,v3}) generate patterns with O(n^k) complexity due to the comma separator being within the matched character class, causing ambiguous backtracking across k variables. When matched against a maliciously crafted URI, this can result in catastrophic backtracking and uncontrolled resource consumption, leading to denial of service. This vulnerability is fixed in 2.9.0.
Severity
7.5 (High)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-09 14:36 UTC
CWE
- CWE-1333 - Inefficient Regular Expression Complexity
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/sporkmonger/addressable/securi… | x_refsource_CONFIRM |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| sporkmonger | addressable |
Affected:
>= 2.3.0, < 2.9.0
|
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CVE-2026-35458 (GCVE-0-2026-35458)
Vulnerability from cvelistv5 – Published: 2026-04-07 14:24 – Updated: 2026-04-09 14:20
VLAI
EPSS
VEX
Title
Gotenberg has a ReDoS via extraHttpHeaders scope feature
Summary
Gotenberg is an API for converting document formats. In 8.29.1 and earlier, Gotenberg uses dlclark/regexp2 to compile user-supplied scope patterns without setting a proper timeout. Users with access to features using this logic can hang workers indefinitely.
Severity
9.8 (Critical)
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-09 14:20 UTC
CWE
- CWE-1333 - Inefficient Regular Expression Complexity
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/gotenberg/gotenberg/security/a… | x_refsource_CONFIRM |
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CVE-2026-35213 (GCVE-0-2026-35213)
Vulnerability from cvelistv5 – Published: 2026-04-06 20:08 – Updated: 2026-06-23 15:51
VLAI
EPSS
VEX
Title
Regular Expression Denial of Service (ReDoS) in @hapi/content HTTP header parsing
Summary
@hapi/content provided HTTP Content-* headers parsing. All versions of @hapi/content through 6.0.0 are vulnerable to Regular Expression Denial of Service (ReDoS) via crafted HTTP header values. Three regular expressions used to parse Content-Type and Content-Disposition headers contain patterns susceptible to catastrophic backtracking. This vulnerability is fixed in 6.0.1.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-07 14:01 UTC
CWE
- CWE-1333 - Inefficient Regular Expression Complexity
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/hapijs/content/security/adviso… | x_refsource_CONFIRM |
| https://github.com/hapijs/content/pull/38 | x_refsource_MISC |
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CVE-2026-35041 (GCVE-0-2026-35041)
Vulnerability from cvelistv5 – Published: 2026-04-09 14:55 – Updated: 2026-04-09 16:15
VLAI
EPSS
VEX
Title
ReDoS in fast-jwt when using RegExp in allowed* leading to CPU exhaustion during token verification
Summary
fast-jwt provides fast JSON Web Token (JWT) implementation. From 5.0.0 to 6.2.0, a denial-of-service condition exists in fast-jwt when the allowedAud verification option is configured using a regular expression. Because the aud claim is attacker-controlled and the library evaluates it against the supplied RegExp, a crafted JWT can trigger catastrophic backtracking in the JavaScript regex engine, resulting in significant CPU consumption during verification. This vulnerability is fixed in 6.2.1.
Severity
4.2 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-09 16:14 UTC
CWE
- CWE-1333 - Inefficient Regular Expression Complexity
Assigner
References
4 references
| URL | Tags |
|---|---|
| https://github.com/nearform/fast-jwt/security/adv… | x_refsource_CONFIRM |
| https://github.com/nearform/fast-jwt/pull/595 | x_refsource_MISC |
| https://github.com/nearform/fast-jwt/commit/b0be0… | x_refsource_MISC |
| https://github.com/nearform/fast-jwt/releases/tag… | x_refsource_MISC |
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CVE-2026-34939 (GCVE-0-2026-34939)
Vulnerability from cvelistv5 – Published: 2026-04-03 22:52 – Updated: 2026-04-06 19:05
VLAI
EPSS
VEX
Title
PraisonAI: ReDoS via Unvalidated User-Controlled Regex in MCPToolIndex.search_tools()
Summary
PraisonAI is a multi-agent teams system. Prior to version 4.5.90, MCPToolIndex.search_tools() compiles a caller-supplied string directly as a Python regular expression with no validation, sanitization, or timeout. A crafted regex causes catastrophic backtracking in the re engine, blocking the Python thread for hundreds of seconds and causing a complete service outage. This issue has been patched in version 4.5.90.
Severity
6.5 (Medium)
SSVC
Exploitation: poc
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-04-06 19:05 UTC
CWE
- CWE-1333 - Inefficient Regular Expression Complexity
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/MervinPraison/PraisonAI/securi… | x_refsource_CONFIRM |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| MervinPraison | PraisonAI |
Affected:
< 4.5.90
|
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CVE-2026-33671 (GCVE-0-2026-33671)
Vulnerability from cvelistv5 – Published: 2026-03-26 21:20 – Updated: 2026-03-27 20:00
VLAI
EPSS
VEX
Title
Picomatch has a ReDoS vulnerability via extglob quantifiers
Summary
Picomatch is a glob matcher written JavaScript. Versions prior to 4.0.4, 3.0.2, and 2.3.2 are vulnerable to Regular Expression Denial of Service (ReDoS) when processing crafted extglob patterns. Certain patterns using extglob quantifiers such as `+()` and `*()`, especially when combined with overlapping alternatives or nested extglobs, are compiled into regular expressions that can exhibit catastrophic backtracking on non-matching input. Applications are impacted when they allow untrusted users to supply glob patterns that are passed to `picomatch` for compilation or matching. In those cases, an attacker can cause excessive CPU consumption and block the Node.js event loop, resulting in a denial of service. Applications that only use trusted, developer-controlled glob patterns are much less likely to be exposed in a security-relevant way. This issue is fixed in picomatch 4.0.4, 3.0.2 and 2.3.2. Users should upgrade to one of these versions or later, depending on their supported release line. If upgrading is not immediately possible, avoid passing untrusted glob patterns to `picomatch`. Possible mitigations include disabling extglob support for untrusted patterns by using `noextglob: true`, rejecting or sanitizing patterns containing nested extglobs or extglob quantifiers such as `+()` and `*()`, enforcing strict allowlists for accepted pattern syntax, running matching in an isolated worker or separate process with time and resource limits, and applying application-level request throttling and input validation for any endpoint that accepts glob patterns.
Severity
7.5 (High)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-03-27 14:12 UTC
CWE
- CWE-1333 - Inefficient Regular Expression Complexity
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://github.com/micromatch/picomatch/security/… | x_refsource_CONFIRM |
| https://github.com/micromatch/picomatch/commit/5e… | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| micromatch | picomatch |
Affected:
>= 4.0.0, < 4.0.4
Affected: >= 3.0.0, < 3.0.2 Affected: < 2.3.2 |
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CVE-2026-33169 (GCVE-0-2026-33169)
Vulnerability from cvelistv5 – Published: 2026-03-23 23:07 – Updated: 2026-03-24 15:46
VLAI
EPSS
VEX
Title
Rails Active Support has a possible ReDoS vulnerability in number_to_delimited
Summary
Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. `NumberToDelimitedConverter` uses a lookahead-based regular expression with `gsub!` to insert thousands delimiters. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, the interaction between the repeated lookahead group and `gsub!` can produce quadratic time complexity on long digit strings. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-03-24 15:45 UTC
CWE
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://github.com/rails/rails/security/advisorie… | x_refsource_CONFIRM |
| https://github.com/rails/rails/commit/29154f1097d… | x_refsource_MISC |
| https://github.com/rails/rails/commit/b54a4b373c6… | x_refsource_MISC |
| https://github.com/rails/rails/commit/ec1a0e215ef… | x_refsource_MISC |
| https://github.com/rails/rails/releases/tag/v7.2.3.1 | x_refsource_MISC |
| https://github.com/rails/rails/releases/tag/v8.0.4.1 | x_refsource_MISC |
| https://github.com/rails/rails/releases/tag/v8.1.2.1 | x_refsource_MISC |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| rails | activesupport |
Affected:
>= 8.1.0.beta1, < 8.1.2.1
Affected: >= 8.0.0.beta1, < 8.0.4.1 Affected: < 7.2.3.1 |
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CVE-2026-33079 (GCVE-0-2026-33079)
Vulnerability from cvelistv5 – Published: 2026-05-06 17:25 – Updated: 2026-08-28 12:04
VLAI
EPSS
VEX
Title
Mistune ReDoS in LINK_TITLE_RE allows denial of service with crafted Markdown titles
Summary
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.
Severity
SSVC
Exploitation: poc
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-06 19:02 UTC
CWE
- CWE-1333 - Inefficient Regular Expression Complexity
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://github.com/lepture/mistune/security/advis… | x_refsource_CONFIRM |
| https://github.com/lepture/mistune/blob/df23edd60… | x_refsource_MISC |
| https://access.redhat.com/security/cve/CVE-2026-33079 | vdb-entryx_refsource_REDHAT |
| https://bugzilla.redhat.com/show_bug.cgi?id=2467298 | issue-trackingx_refsource_REDHAT |
| https://security.access.redhat.com/data/csaf/v2/v… | x_sadp-csaf-vex |
| https://access.redhat.com/errata/RHSA-2026:43038 | vendor-advisoryx_refsource_REDHAT |
| https://access.redhat.com/errata/RHSA-2026:60520 | vendor-advisoryx_refsource_REDHAT |
Impacted products
22 products
| Vendor | Product | Version | |
|---|---|---|---|
| lepture | mistune |
Affected:
>=3.0.0a1, <= 3.2.0
|
|
| Red Hat | Red Hat Migration Toolkit for Applications 8.2 |
Unaffected:
1784109883 , < *
(rpm)
cpe:/a:redhat:migration_toolkit_applications:8.2::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073866 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073936 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073873 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073459 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073611 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073451 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787076778 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787077779 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787076481 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787074331 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073913 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787074078 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073929 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073605 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073546 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073717 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073713 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI 3.4 |
Unaffected:
1787073593 , < *
(rpm)
cpe:/a:redhat:openshift_ai:3.4::el9 |
|
| Red Hat | Red Hat OpenShift AI (RHOAI) |
cpe:/a:redhat:openshift_ai
|
|
| Red Hat | Red Hat Satellite 6 |
cpe:/a:redhat:satellite:6
|
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Mitigation
Architecture and Design
Use regular expressions that do not support backtracking, e.g. by removing nested quantifiers.
Mitigation
System Configuration
Set backtracking limits in the configuration of the regular expression implementation, such as PHP's pcre.backtrack_limit. Also consider limits on execution time for the process.
Mitigation
Implementation
Do not use regular expressions with untrusted input. If regular expressions must be used, avoid using backtracking in the expression.
Mitigation
Implementation
Limit the length of the input that the regular expression will process.
CAPEC-492: Regular Expression Exponential Blowup
An adversary may execute an attack on a program that uses a poor Regular Expression(Regex) implementation by choosing input that results in an extreme situation for the Regex. A typical extreme situation operates at exponential time compared to the input size. This is due to most implementations using a Nondeterministic Finite Automaton(NFA) state machine to be built by the Regex algorithm since NFA allows backtracking and thus more complex regular expressions.