VulnerabilityPublished 7 Mar 2026Updated 9 Mar 2026

CVE-2026-29779: lyc8503 UptimeFlare · Information Exposure

Affects lyc8503 UptimeFlareSource CVE Database V5

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Not known to be exploited · CVSS 7.5 High.

Data as of 30 Oct 2026, 06:59 UTC

CVSS 3.1 base score

7.5High

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 23% 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:H/I:N/A:N

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

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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 7 Mar 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 29 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.
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

Affected software

Product	Affected	Fixed in
lyc8503UptimeFlare	Affected =< 377a5963c66ba9a798abebfe8d80378b053435e9	Fixed in–

AI-suggested

To mitigate this vulnerability, organizations should immediately update UptimeFlare to a version including commit 377a596 or later, which properly segregates client and server configuration exports. Developers should audit their codebase to ensure that sensitive server-only configurations are never imported or bundled into client-side JavaScript. Implement strict code review processes focusing on the separation of client and server contexts, especially in serverless or edge computing environments. Employ automated static analysis tools to detect accidental exposure of sensitive data in frontend bundles. Additionally, rotate any potentially exposed secrets or credentials that may have been leaked prior to patching. Consider implementing runtime monitoring and alerting for unusual access patterns to status pages. Finally, educate development teams on secure coding practices related to configuration management and data exposure in serverless architectures.

Description

UptimeFlare is a serverless uptime monitoring & status page solution, powered by Cloudflare Workers. Prior to commit 377a596, configuration file uptime.config.ts exports both pageConfig (safe for client use) and workerConfig (server-only, contains sensitive data) from the same module. Due to pages/incidents.tsx importing and using workerConfig directly inside client-side component code, the entire workerConfig object was included in the client-side JavaScript bundle served to all visitors. This issue has been patched via commit 377a596.

Impact

The primary impact of this vulnerability is the unauthorized disclosure of sensitive server-side configuration data embedded in the workerConfig object. This exposure compromises confidentiality, potentially revealing secrets such as API keys, tokens, internal endpoints, or other sensitive parameters that could be leveraged by attackers for further exploitation. Although the vulnerability does not directly affect system integrity or availability, the leaked information could enable attackers to craft targeted attacks, escalate privileges, or bypass security controls. Organizations relying on UptimeFlare for uptime monitoring and status pages may inadvertently expose critical internal configuration details to any visitor, including malicious actors. This could lead to reputational damage, increased risk of intrusion, and potential data breaches. Since the vulnerability requires no authentication or user interaction, it is easily exploitable by anyone accessing the affected pages. The widespread use of Cloudflare Workers and serverless monitoring solutions increases the potential attack surface, especially for organizations that have not applied the patch.

CWE-200Exposure of Sensitive Information to an Unauthorized Actor (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #20OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Subverting Environment Variable Values (opens in a new tab)
ICMP Echo Request Ping (opens in a new tab)
TCP SYN Scan (opens in a new tab)
Enumerate Mail Exchange (MX) Records (opens in a new tab)
DNS Zone Transfers (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 14 Mar 2026, 19:56 UTC

WeaknessesCWE-200

Technical details

References

Community reviews

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