GHSA-c2f4-jgmc-q2r5 CVE-2025-58767
REXML has DoS condition when parsing malformed XML file
- Severity
- 0.0 / 10
- Medium · CVSS 4.0
- Exploit chance (EPSS)
- 0.25%
- Chance of exploitation in the next 30 days. Higher than 16.37% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-400 Uncontrolled Resource Consumption
- CWE-776 Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
- Fix
3.4.2- Upgrade rexml to this version or later
Description
Impact
The REXML gems from 3.3.3 to 3.4.1 have a DoS vulnerability when parsing XML containing multiple XML declarations. If you need to parse untrusted XMLs, you may be impacted to these vulnerabilities.
Patches
REXML gems 3.4.2 or later include the patches to fix these vulnerabilities.
Workarounds
Don't parse untrusted XMLs.
References
- https://www.ruby-lang.org/en/news/2025/09/18/dos-rexml-cve-2025-58767/ : An announcement on www.ruby-lang.org
Affected versions
RubyGems
| Package | Vulnerable | Fixed in |
|---|---|---|
| rexml | >= 3.3.3, < 3.4.2 |
3.4.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
rexml RubyGems → 3.4.2
- bundler
bundle update rexml # Gemfile: gem "rexml", ">= 3.4.2"
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U
- Attack vector
- Local
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- Low
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
- Exploit maturity
- Unreported
CVSS 3.1 5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Weakness
CWE-400: Uncontrolled Resource Consumption
The product does not properly control the allocation and maintenance of a limited resource.
How to prevent it
- Architecture and Design: Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
- Architecture and Design: Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
- Architecture and Design: Ensure that protocols have specific limits of scale placed on them.
- Implementation: Ensure that all failures in resource allocation place the system into a safe posture.
CWE-776: Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')
The product uses XML documents and allows their structure to be defined with a Document Type Definition (DTD), but it does not properly control the number of recursive definitions of entities.
How to prevent it
- Operation: If possible, prohibit the use of DTDs or use an XML parser that limits the expansion of recursive DTD entities.
- Implementation: Before parsing XML files with associated DTDs, scan for recursive entity declarations and do not continue parsing potentially explosive content.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-2rxp-v6pw-ch6m REXML ReDoS vulnerability | High | Also affects rexml |
| GHSA-vmwr-mc7x-5vc3 REXML denial of service vulnerability | Medium | Also affects rexml |
| GHSA-5866-49gr-22v4 REXML DoS vulnerability | High | Also affects rexml |
| GHSA-r55c-59qm-vjw6 REXML DoS vulnerability | High | Also affects rexml |
| GHSA-4xqq-m2hx-25v8 REXML denial of service vulnerability | Medium | Also affects rexml |
| GHSA-vg3r-rm7w-2xgh REXML contains a denial of service vulnerability | Medium | Also affects rexml |
| GHSA-8cr8-4vfw-mr7h REXML round-trip instability | High | Also affects rexml |
| GHSA-cggf-277g-3q54 pypdf has possible large memory usage when parsing page tree | High | Same weakness, CWE-400 |
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