VulnerabilityPublished 27 Sep 2026Updated 30 Sep 2026

CVE-2026-101087: nezhahq nezha · Server-Side Request Forgery (SSRF)

Affects nezhahq nezhaSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium : upgrade to 2.3.3 when convenient.

Data as of 10 Nov 2026, 23:24 UTC

CVSS 4.0 base score

5.3Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 17% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.3.3

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L

Attack Vector: Network
Attack Complexity: Low
Attack Requirements: None
Privileges Required: Low
User Interaction: None
Vulnerable system confidentiality: None
Vulnerable system integrity: Low
Vulnerable system availability: None
Subsequent system confidentiality: Low
Subsequent system integrity: Low
Subsequent system availability: Low

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

Attack Vector: Network: The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, 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: The attacker must take no measurable action to exploit the vulnerability. The attack requires no target-specific circumvention to exploit the vulnerability. An attacker can expect repeatable success against the vulnerable system.
Attack Requirements: None: The successful attack does not depend on the deployment and execution conditions of the vulnerable system. The attacker can expect to be able to reach the vulnerability and execute the exploit under all or most instances of the vulnerability.
Privileges Required: Low: The attacker requires privileges that provide basic capabilities that are typically limited to settings and resources owned by a single low-privileged user. Alternatively, an attacker with Low privileges has the ability to access only non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without interaction from any human user, other than the attacker.
Vulnerable system confidentiality: None: There is no loss of confidentiality within the Vulnerable System.
Vulnerable system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Vulnerable System.
Vulnerable system availability: None: There is no impact to availability within the Vulnerable System.
Subsequent system confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the Subsequent System.
Subsequent system integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact to the Subsequent System.
Subsequent system 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 Subsequent System 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 Subsequent System.

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 27 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 10 Nov 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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 nezha and github.com/nezhahq/nezha to 2.3.3.

Affected software

Product	Affected	Fixed in
nezhahqnezha	Affected >=2.0.10 <2.3.3	Fixed in 2.3.3
Gogithub.com/nezhahq/nezha`pkg:golang/github.com/nezhahq/nezha`Other threats	Affected >=2.0.10 <2.3.3	Fixed in 2.3.3

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

AI-suggested

Upgrade Nezha to version 2.3.3 or later, which includes a fix blocking the problematic IPv6 transition prefixes 2002::/16 and 64:ff9b:1::/48. This official fix prevents the SSRF vulnerability by properly restricting these addresses in the URL validation process.

Description

Nezha versions 2.0.10 through 2.3.2 contain a server-side request forgery (SSRF) vulnerability due to incomplete denylist coverage of IPv6 transition ranges in the HTTP client used for validating user-configurable webhook URLs. Authenticated users can exploit this to cause the dashboard to send requests to certain IPv6 endpoints that are normally restricted. The vulnerability is fixed in version 2.3.3 by blocking the problematic IPv6 prefixes.

Impact

An authenticated user can exploit this vulnerability to perform SSRF attacks targeting IPv6 endpoints within the dashboard's network that are normally restricted. However, the impact is limited because no direct access to IPv4 metadata, loopback, or private network HTTP requests has been demonstrated, and exploitation requires unusual or non-standard routing configurations for IPv6 transition ranges.

Summary

Nezha versions 2.0.10 through 2.3.2 use a restricted HTTP client to validate user-configurable notification and DDNS webhook URLs. However, the denylist did not cover IPv6 transition ranges, specifically the 6to4 prefix 2002::/16 and the IPv4/IPv6 translation prefix 64:ff9b:1::/48. These addresses pass Go's netip.Addr.IsGlobalUnicast check, causing the URL validator to accept them. An authenticated user able to configure a webhook may cause the dashboard to issue requests to otherwise restricted IPv6 endpoints, but no direct access to IPv4 metadata, loopback, or private network HTTP requests has been demonstrated. The issue is resolved in version 2.3.3 by blocking these prefixes.

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 5 Oct 2026, 20:33 UTC

Technical details

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