VulnerabilityPublished 5 Feb 2026Updated 12 Feb 2026

CVE-2025-58190: golang.org/x/net/html · Loop with Unreachable Exit Condition

Affects golang.org/x/net/htmlSource CVE Database V5

Not known to be exploited · CVSS 5.3 Medium : upgrade to 0.45.0 when convenient.

Data as of 26 Oct 2026, 10:12 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 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.45.0

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 5 Feb 2026
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 or the CVSS exploit maturity 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.

What to do

Upgrade golang.org/x/net/html to 0.45.0.

Affected software

Product	Affected	Fixed in
golang.org/x/netgolang.org/x/net/html	Affected <0.45.0	Fixed in 0.45.0
Gogolang.org/x/net/html`pkg:golang/golang.org/x/net/html`Other threats	Affected =0	Fixed in–
Gogolang.org/x/net/html`pkg:golang/golang.org/x/net/html`Other threats	Affected <0.45.0	Fixed in 0.45.0

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

AI-suggested

Monitor official golang.org/x/net/html package repositories and security advisories for the release of a patch addressing CVE-2025-58190 and apply updates promptly once available.
Implement input validation to filter or sanitize incoming HTML content before parsing, reducing the risk of triggering the infinite loop.
Introduce parsing timeouts or resource limits in applications using html.Parse to prevent indefinite CPU consumption during parsing.
Employ runtime monitoring and alerting for abnormal CPU usage patterns in services that parse HTML content, enabling rapid detection of potential exploitation attempts.
Where feasible, isolate HTML parsing components in separate processes or containers to limit the blast radius of a DoS condition.
Conduct code reviews and security testing focused on input handling and parsing logic in Go applications to identify similar vulnerabilities.
Educate developers and DevOps teams about this vulnerability and encourage secure coding practices around third-party library usage.
Consider alternative HTML parsing libraries or approaches if immediate patching is not possible, ensuring they do not exhibit similar infinite loop behaviors.

Description

The html.Parse function in golang.org/x/net/html has an infinite parsing loop when processing certain inputs, which can lead to denial of service (DoS) if an attacker provides specially crafted HTML content.

Impact

For European organizations, the primary impact of CVE-2025-58190 is the potential for denial of service attacks against Go-based applications that parse HTML content using the vulnerable golang.org/x/net/html package. This can lead to service outages, degraded performance, and increased operational costs due to resource exhaustion. Organizations providing web services, APIs, or content processing pipelines that accept or handle untrusted HTML inputs are at risk. The vulnerability does not compromise data confidentiality or integrity but can disrupt business continuity and availability of critical services. In sectors such as finance, telecommunications, government, and critical infrastructure, even temporary service disruptions can have significant operational and reputational consequences. Additionally, the ease of exploitation without authentication or user interaction increases the risk of automated or opportunistic attacks. The lack of known exploits in the wild suggests a window of opportunity for proactive mitigation before widespread exploitation occurs. European entities relying on Go for backend services, cloud-native applications, or microservices architectures should assess their exposure and prioritize remediation to maintain service availability and resilience.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 13 Feb 2026, 06:49 UTC

WeaknessesCWE-835

Technical details

References

Community reviews

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