CVE-2025-58185VulnerabilityPublished 29 Oct 2025Updated 4 Nov 2025

CVE-2025-58185: Go standard library encoding/asn1 · Uncontrolled Resource Consumption

Affects Go standard library encoding/asn1Source CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

5.3Medium

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

EPSS: 0.5% chance of exploitation in 30 days – higher than 46% 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:L

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

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: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

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 2026-10-26.

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/encoding/asn1`pkg:golang/github.com/golang/go/src/encoding/asn1`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 fixed version of the Go standard library once the patch for CVE-2025-58185 is released. Monitor official Go project channels for updates. 2. Implement strict input validation and sanity checks on ASN.1 DER data before parsing to detect and reject malformed or suspicious payloads. 3. Employ resource usage limits such as memory quotas or timeouts on processes or containers running Go applications that parse ASN.1 data to prevent resource exhaustion. 4. Use sandboxing or isolation techniques to limit the impact of potential DoS attacks on critical systems. 5. Monitor application logs and system metrics for unusual memory consumption patterns indicative of exploitation attempts. 6. Where feasible, consider alternative parsing libraries with better resource control or hardened ASN.1 parsers. 7. Educate developers and security teams about the risks of parsing untrusted ASN.1 data and encourage secure coding practices. 8. Conduct penetration testing and fuzzing focused on ASN.1 DER inputs to identify similar vulnerabilities proactively.

Description

To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle

Impact

For European organizations, the primary impact of CVE-2025-58185 is on availability. Systems that rely on Go's encoding/asn1 package to parse DER-encoded data—such as TLS certificate handling, cryptographic operations, or network protocol implementations—could be disrupted by memory exhaustion attacks. This can lead to denial of service conditions, affecting critical infrastructure, financial services, telecommunications, and cloud service providers. The vulnerability does not compromise confidentiality or integrity but can cause service outages, impacting business continuity and potentially leading to financial losses and reputational damage. Organizations with high reliance on Go-based microservices or backend systems exposed to untrusted inputs are particularly vulnerable. The lack of authentication or user interaction requirements increases the risk of remote exploitation. Although no known exploits exist yet, the medium severity and ease of exploitation warrant proactive mitigation. The impact is heightened in environments with limited memory resources or where resource usage is not tightly controlled.

Summary

CVE-2025-58185 is a vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) found in the Go programming language's standard library, specifically in the encoding/asn1 package. The vulnerability arises when the ASN.1 DER parser processes a maliciously crafted payload that triggers excessive memory allocation. ASN.1 (Abstract Syntax Notation One) is widely used for encoding data structures in telecommunications and cryptographic protocols. The flaw allows an attacker to cause the Go application to allocate large amounts of memory, potentially exhausting system resources and causing a denial of service (DoS). The vulnerability affects all Go versions up to and including 1.25.0. The CVSS v3.1 base score is 5.3, indicating medium severity, with the vector AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L, meaning it is remotely exploitable without authentication or user interaction, and impacts only availability. No patches or exploits are currently publicly available, but the vulnerability is officially published and reserved since August 2025. This issue is critical for applications that parse untrusted ASN.1 DER data, such as certificate processing, cryptographic protocols, or network services implemented in Go. Attackers could exploit this by sending crafted DER payloads to vulnerable services, causing them to consume excessive memory and crash or become unresponsive.

CWE-400Uncontrolled Resource Consumption (opens in a new tab)
Class weaknessLikelihood of exploit: High
The product does not properly control the allocation and maintenance of a limited resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
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.
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.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Regular Expression Exponential Blowup (opens in a new tab)
Sustained Client Engagement (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 5 Nov 2025, 23:22 UTC

WeaknessesCWE-400

Technical details

References

Community reviews

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