jekyll-4.3.4.gem: 5 vulnerabilities (highest severity is: 7.5)

[mend-bolt-for-github]

Vulnerable Library - jekyll-4.3.4.gem

Path to dependency file: /Gemfile.lock

Path to vulnerable library: /Gemfile.lock

Vulnerabilities

Vulnerability	Severity	CVSS	Dependency	Type	Fixed in (jekyll version)	Remediation Possible**
CVE-2026-54904	High	7.5	concurrent-ruby-1.3.4.gem	Transitive	N/A*	❌
CVE-2026-35611	High	7.5	addressable-2.8.7.gem	Transitive	N/A*	❌
CVE-2026-54905	Medium	5.3	concurrent-ruby-1.3.4.gem	Transitive	N/A*	❌
CVE-2026-54906	Medium	4.0	concurrent-ruby-1.3.4.gem	Transitive	N/A*	❌
CVE-2025-58767	Medium	4.0	rexml-3.4.0.gem	Transitive	N/A*	❌

*For some transitive vulnerabilities, there is no version of direct dependency with a fix. Check the "Details" section below to see if there is a version of transitive dependency where vulnerability is fixed.

**In some cases, Remediation PR cannot be created automatically for a vulnerability despite the availability of remediation

Details

CVE-2026-54904

Vulnerable Library - concurrent-ruby-1.3.4.gem

Modern concurrency tools including agents, futures, promises, thread pools, actors, supervisors, and more. Inspired by Erlang, Clojure, Go, JavaScript, actors, and classic concurrency patterns.

Library home page: https://rubygems.org/gems/concurrent-ruby-1.3.4.gem

Path to dependency file: /Gemfile.lock

Path to vulnerable library: /Gemfile.lock

Dependency Hierarchy:

• jekyll-4.3.4.gem (Root Library)
  • i18n-1.14.6.gem
    • ❌ concurrent-ruby-1.3.4.gem (Vulnerable Library)

Found in base branch: source

Vulnerability Details

concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::AtomicReference#update can enter a permanent busy retry loop when the current value is Float::NAN. The issue is caused by the interaction between AtomicReference#update, which retries until compare_and_set(old_value, new_value) succeeds; Numeric compare_and_set, which checks old == old_value before attempting the underlying atomic swap.; and Ruby NaN semantics, where Float::NAN == Float::NAN is always false. As a result, once an AtomicReference contains Float::NAN, calling #update repeatedly evaluates the caller's block and never returns. In services that store externally derived numeric values in an AtomicReference, this can cause CPU exhaustion or permanent request/job hangs. This vulnerability is fixed in 1.3.7.

Publish Date: 2026-06-24

URL: CVE-2026-54904

CVSS 3 Score Details (7.5)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: None
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2026-06-19

Fix Resolution: https://github.com/ruby-concurrency/concurrent-ruby.git - v1.3.7

Step up your Open Source Security Game with Mend here

CVE-2026-35611

Vulnerable Library - addressable-2.8.7.gem

Addressable is an alternative implementation to the URI implementation that is part of Ruby's standard library. It is flexible, offers heuristic parsing, and additionally provides extensive support for IRIs and URI templates.

Library home page: https://rubygems.org/gems/addressable-2.8.7.gem

Path to dependency file: /Gemfile.lock

Path to vulnerable library: /Gemfile.lock

Dependency Hierarchy:

• jekyll-4.3.4.gem (Root Library)
  • ❌ addressable-2.8.7.gem (Vulnerable Library)

Found in base branch: source

Vulnerability Details

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.

Publish Date: 2026-04-07

URL: CVE-2026-35611

CVSS 3 Score Details (7.5)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Network
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: None
  • Availability Impact: High

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2026-04-07

Fix Resolution: https://github.com/sporkmonger/addressable.git - addressable-2.9.0

Step up your Open Source Security Game with Mend here

CVE-2026-54905

Vulnerable Library - concurrent-ruby-1.3.4.gem

Modern concurrency tools including agents, futures, promises, thread pools, actors, supervisors, and more. Inspired by Erlang, Clojure, Go, JavaScript, actors, and classic concurrency patterns.

Library home page: https://rubygems.org/gems/concurrent-ruby-1.3.4.gem

Path to dependency file: /Gemfile.lock

Path to vulnerable library: /Gemfile.lock

Dependency Hierarchy:

• jekyll-4.3.4.gem (Root Library)
  • i18n-1.14.6.gem
    • ❌ concurrent-ruby-1.3.4.gem (Vulnerable Library)

Found in base branch: source

Vulnerability Details

concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReentrantReadWriteLock can incorrectly grant a write lock after one thread acquires the read lock 32,768 times. The lock stores a thread's local read and write hold counts in one integer. The low 15 bits are used for the read hold count, and bit 15 is used as WRITE_LOCK_HELD. After 32,768 reentrant read acquisitions, the local read count crosses into the write-lock bit. try_write_lock then treats the thread as already holding a write lock and returns true without setting the global RUNNING_WRITER bit. This breaks the core mutual-exclusion guarantee: the caller is told it has a write lock, but other threads can still hold or acquire read locks at the same time. This vulnerability is fixed in 1.3.7.

Publish Date: 2026-06-24

URL: CVE-2026-54905

CVSS 3 Score Details (5.3)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Local
  • Attack Complexity: Low
  • Privileges Required: Low
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: Low
  • Integrity Impact: Low
  • Availability Impact: Low

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2026-06-19

Fix Resolution: https://github.com/ruby-concurrency/concurrent-ruby.git - v1.3.7

Step up your Open Source Security Game with Mend here

CVE-2026-54906

Vulnerable Library - concurrent-ruby-1.3.4.gem

Modern concurrency tools including agents, futures, promises, thread pools, actors, supervisors, and more. Inspired by Erlang, Clojure, Go, JavaScript, actors, and classic concurrency patterns.

Library home page: https://rubygems.org/gems/concurrent-ruby-1.3.4.gem

Path to dependency file: /Gemfile.lock

Path to vulnerable library: /Gemfile.lock

Dependency Hierarchy:

• jekyll-4.3.4.gem (Root Library)
  • i18n-1.14.6.gem
    • ❌ concurrent-ruby-1.3.4.gem (Vulnerable Library)

Found in base branch: source

Vulnerability Details

concurrent-ruby is a modern concurrency tools for Ruby. Prior to 1.3.7, Concurrent::ReadWriteLock#release_write_lock does not verify that the calling thread acquired the write lock. Any thread with access to the lock object can release an active write lock held by another thread. A second writer can then enter its critical section while the first writer is still running. Concurrent::ReadWriteLock#release_read_lock also decrements the shared counter even when no read lock is held. Calling it on a fresh lock changes the counter from 0 to -1, after which normal read acquisition raises Concurrent::ResourceLimitError. This is a synchronization correctness issue in the public Concurrent::ReadWriteLock API. This vulnerability is fixed in 1.3.7.

Publish Date: 2026-06-24

URL: CVE-2026-54906

CVSS 3 Score Details (4.0)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Local
  • Attack Complexity: High
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: Low
  • Availability Impact: Low

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2026-06-19

Fix Resolution: https://github.com/ruby-concurrency/concurrent-ruby.git - v1.3.7

Step up your Open Source Security Game with Mend here

CVE-2025-58767

Vulnerable Library - rexml-3.4.0.gem

An XML toolkit for Ruby

Library home page: https://rubygems.org/gems/rexml-3.4.0.gem

Path to dependency file: /Gemfile.lock

Path to vulnerable library: /Gemfile.lock

Dependency Hierarchy:

• jekyll-4.3.4.gem (Root Library)
  • kramdown-parser-gfm-1.1.0.gem
    • kramdown-2.5.1.gem
      • ❌ rexml-3.4.0.gem (Vulnerable Library)

Found in base branch: source

Vulnerability Details

REXML is an XML toolkit for Ruby. The REXML gems from 3.3.3 to 3.4.1 has a DoS vulnerability when parsing XML containing multiple XML declarations. If you need to parse untrusted XMLs, you may be impacted to these vulnerabilities. The REXML gem 3.4.2 or later include the patches to fix these vulnerabilities.

Publish Date: 2025-09-17

URL: CVE-2025-58767

CVSS 3 Score Details (4.0)

Base Score Metrics:

• Exploitability Metrics:
  • Attack Vector: Local
  • Attack Complexity: Low
  • Privileges Required: None
  • User Interaction: None
  • Scope: Unchanged
• Impact Metrics:
  • Confidentiality Impact: None
  • Integrity Impact: None
  • Availability Impact: Low

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Origin: GHSA-c2f4-jgmc-q2r5

Release Date: 2025-09-17

Fix Resolution: rexml - 3.4.2,https://github.com/ruby/rexml.git - v3.4.2

Step up your Open Source Security Game with Mend here

[mend-bolt-for-github]

✔️ This issue was automatically closed by Mend because the vulnerable library in the specific branch(es) was either marked as ignored or it is no longer part of the Mend inventory.

[mend-bolt-for-github]

ℹ️ This issue was automatically re-opened by Mend because the vulnerable library in the specific branch(es) has been detected in the Mend inventory.