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Atomicorp WAF Research Note: CVE-2026-80350

OneUptime before 12.0.7 Server-Side Request Forgery via IPv4-Mapped IPv6 Webhook URL

CVE Details

Status: Attack Blocked by Atomicorp
  • Already protected by existing Atomicorp WAF rules
  • Protection status: Understanding Atomicorp WAF Protection Status
  • CVE: CVE-2026-80350
  • Name: OneUptime before 12.0.7 Server-Side Request Forgery via IPv4-Mapped IPv6 Webhook URL
  • Severity: High
  • CVSS: 7.1 (v4.0) (High)
  • CVSS version: 4.0
  • CVSS source: VulnCheck CNA
  • CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    • Attack vector: Network
    • Attack complexity: Low
    • Attack requirements: None
    • Privileges required: Low
    • User interaction: None
    • Vulnerable-system confidentiality: High
    • Vulnerable-system integrity: Low
    • Vulnerable-system availability: None
    • Subsequent-system confidentiality: None
    • Subsequent-system integrity: None
    • Subsequent-system availability: None
    • Scope: X
  • CWE: CWE-918 — Server-Side Request Forgery (SSRF)
  • Related CAPEC attack patterns (via MITRE CWE relationships): CAPEC-664
  • Vendor: OneUptime
  • Vulnerable product: OneUptime
  • CVE published: 2026-08-26
  • CVE last modified: 2026-08-26
  • EPSS: 0.0029; 20.9th percentile (FIRST )
  • Latest Update: 2026-09-06
  • Selected Rule IDs observed: 337109 , 337110 , 340162 , 340163 , 344360 , 398001 , 398008 , 398021 , 398022
  • Matching rules: 9; rules with blocking actions: 7
  • Would-block Rule IDs: 337109 , 337110 , 340162 , 340163 , 344360 , 398021 , 398022
  • Request surfaces inspected: JSON request data, Request URI, Request argument names, Request arguments, Request cookies, SOAP request data, XML request data

Vulnerability Description

OneUptime’s webhook target check rejects private and loopback addresses given in IPv4 form and a small set of IPv6 forms, but has no case for the IPv4-mapped IPv6 range. The webhook delivery path calls SSRFProtection.validateWebhookTargetIsSafe, and the host-literal screening inside Common/Server/Utils/SSRFProtection.ts, performed by isBlockedHostnameLiteral, rejects private and loopback IPv4 ranges and tests an IPv6 value against the unspecified address, the loopback, the link-local prefix and the unique-local prefixes. A value such as [::ffff:127.0.0.1] matches none of them. The value is also recognised as an address literal rather than a name, so the path that re-checks addresses obtained from resolution is not taken. The HTTP client treats the mapped form as the embedded IPv4 address and connects to it, so an authenticated project member who can configure a webhook can direct the server at loopback services, private network ranges and link-local metadata endpoints, and the response is recorded where the webhook result can be read. Version 12.0.7 adds handling for the mapped range.

  1. Maintain the observed Atomicorp protections. Keep your Atomicorp commercial rules current and confirm that the selected observed rules (337109 , 337110 , 340162 , 340163 , 344360 , 398021 , 398022 ) have not been locally disabled. Atomicorp commercial rules are enabled by default. If you use Atomic WAF, review the applicable policy and rule settings.

  2. Apply the vendor’s remediation. WAF protection is defense in depth and does not replace upgrading or following the affected vendor’s guidance.

    • Affected versions: OneUptime versions earlier than 12.0.7.
    • Recommended upgrade: Upgrade OneUptime to 12.0.7 or later.

  3. Validate after changes. Confirm rule updates are current, review WAF events for the affected application, and test application behavior after vendor upgrades, mitigations, or local policy changes.

Research Notes

Atomicorp WAF protections are designed around attack techniques and exploit behaviors, allowing existing protections to apply across multiple vulnerabilities without requiring a unique rule for every CVE.

Public Vulnerability References

Test or Research Source

  • Source: Atomicorp AI Research Framework
  • Tags: cve, derived, ssrf, waf-probe

Research Note Context

This research note documents exploit-technique analysis associated with this vulnerability and references Atomicorp WAF protections observed during engineering review, testing, or validation activities.

Atomicorp security controls are generally designed to identify and mitigate attack techniques and exploit behaviors rather than individual CVE identifiers. As a result, protections developed for one vulnerability may also apply to related attack variants and future vulnerabilities using similar techniques.

Learn More

Atomicorp develops commercially supported security technologies for web applications, servers, endpoints, workloads, and legacy enterprise platforms.

Organizations interested in protecting systems against exploit techniques associated with vulnerabilities such as this one can learn more about:

  • Atomic ModSecurity Rules: commercially maintained WAF rules for ModSecurity deployments, including protections for web attacks, bots, scanners, malware, exploitation attempts, and emerging vulnerability classes.
  • Atomic WAF: an enterprise web application firewall with Atomicorp rules, centralized management, reporting, authentication controls, and operational tooling.
  • Atomic ModSecurity Integrator: a special licensing option for MSPs, MSSPs, OEMs, VARs, reverse proxy providers, and other integrators who want to incorporate Atomicorp ModSecurity rule technology into their own products or services.
  • Atomic OSSEC: an enterprise OSSEC-based intrusion detection, compliance, and security monitoring platform.
  • Atomic Protector: workload protection for Linux, web, cloud, data center, and hybrid environments.

For additional information, product evaluations, or technical discussions, visit https://www.atomicorp.com/ or https://modsecurity.io/ .