VulnerabilityPublished 29 Oct 2025Updated 20 Nov 2025

CVE-2025-58187: Go standard library crypto/x509 · Inefficient Algorithmic Complexity

Affects Go standard library crypto/x509Source CVE Database V5

Not known to be exploited · CVSS 7.5 High.

Data as of 26 Oct 2026, 09:15 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 34% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

microsoft-security-response-ce

What to do

Affected software

Product	Affected	Fixed in
Gogithub.com/golang/go/src/crypto/x509`pkg:golang/github.com/golang/go/src/crypto/x509`Other threats	Affected =0 =1.25.0	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. Upgrade to a patched version of the Go standard library once it becomes available, as this is the definitive fix for the vulnerability. 2. Until a patch is released, implement input validation and size limits on certificate chains to prevent processing of excessively large or complex certificates. 3. Employ rate limiting and resource usage monitoring on services performing certificate validation to detect and mitigate abnormal CPU consumption patterns. 4. Consider isolating certificate validation processes in separate containers or sandboxes with strict resource quotas to contain potential DoS impacts. 5. Review and harden TLS termination points and certificate validation logic to reject suspicious or non-standard certificates early. 6. Monitor security advisories from the Go project and related ecosystem tools for updates and patches. 7. Conduct internal audits of all services using Go's crypto/x509 package to identify exposure and prioritize remediation efforts. 8. Educate development and operations teams about the vulnerability and encourage proactive incident response planning.

Description

Due to the design of the name constraint checking algorithm, the processing time of some inputs scale non-linearly with respect to the size of the certificate. This affects programs which validate arbitrary certificate chains.

Impact

The primary impact of CVE-2025-58187 is on the availability of services that use the Go crypto/x509 package for certificate validation. An attacker can exploit the inefficient algorithm to cause excessive CPU usage, potentially leading to denial-of-service conditions. For European organizations, this could disrupt critical services such as web servers, API gateways, and internal microservices that rely on Go for TLS certificate validation. Industries with high reliance on secure communications, such as finance, healthcare, and government, may experience service outages or degraded performance. Additionally, cloud service providers and SaaS companies using Go could face scalability and reliability issues. The vulnerability does not affect confidentiality or integrity directly but can indirectly impact business operations and trust due to service unavailability. The absence of required authentication or user interaction lowers the barrier for exploitation, increasing the risk profile. Organizations with automated certificate validation pipelines are particularly vulnerable to large-scale or targeted DoS attacks leveraging this flaw.

CWE-407Inefficient Algorithmic Complexity (opens in a new tab)
Class weaknessLikelihood of exploit: Low
An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 20 Nov 2025, 23:26 UTC

WeaknessesCWE-407

Technical details

References

Community reviews

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