VulnerabilityPublished 1 Mar 2026Updated 2 Mar 2026

CVE-2026-3390: FascinatedBox lily · Out-of-bounds Read

Affects FascinatedBox lilySource CVE Database V5

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Public exploit available · CVSS 4.8 Medium.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 4.0 base score

4.8Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Base metrics

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

Threat metrics

Exploit Maturity: POC

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

Attack Vector: Local: The vulnerable system is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or through terminal emulation (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., using social engineering techniques to trick a legitimate user into opening a malicious document).
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: None: There is no loss of integrity within the Vulnerable System.
Vulnerable 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 Vulnerable 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 Vulnerable System.
Subsequent system confidentiality: None: There is no loss of confidentiality within the Subsequent System or all confidentiality impact is constrained to the Vulnerable System.
Subsequent system integrity: None: There is no loss of integrity within the Subsequent System or all integrity impact is constrained to the Vulnerable System.
Subsequent system availability: None: There is no impact to availability within the Subsequent System or all availability impact is constrained to the Vulnerable System.
Exploit Maturity: POC: Based on threat intelligence sources each of the following must apply: · Proof-of-concept is publicly available · No knowledge of reported attempts to exploit this vulnerability · No knowledge of publicly available solutions used to simplify attempts to exploit the vulnerability

Definitions: FIRST CVSS v4.0 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 1 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CVSS exploit maturity: proof of concept public
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), CVSS vector, the Metasploit, Exploit-DB and nuclei-templates index as of 30 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
FascinatedBoxlily	Affected 2.0 – 2.3 4 affected builds	Fixed in–
GitHubfascinatedbox/lily`pkg:github/fascinatedbox/lily`Other threats	Affected 2.0 – 2.3 4 affected builds	Fixed in–

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AI-suggested

To mitigate CVE-2026-3390, organizations should first restrict local access to systems running affected versions of FascinatedBox lily, ensuring only trusted users have login privileges. Implement strict user account controls and monitor for unusual local activity that might indicate exploitation attempts. Employ runtime protections like memory safety tools (e.g., AddressSanitizer) during development and testing to detect out-of-bounds reads. Regularly audit error reporting outputs to ensure no sensitive data is exposed. Stay alert for vendor updates or community patches and plan for prompt application once released. Additionally, isolate systems running this software in segmented network zones to limit lateral movement if local compromise occurs.

Description

A vulnerability was identified in FascinatedBox lily up to 2.3. This issue affects the function patch_line_end of the file src/lily_build_error.c of the component Error Reporting. The manipulation leads to out-of-bounds read. The attack can only be performed from a local environment. The exploit is publicly available and might be used. The project was informed of the problem early through an issue report but has not responded yet.

Impact

The primary impact of CVE-2026-3390 is limited local information disclosure due to out-of-bounds memory reads. While this does not directly allow remote code execution or privilege escalation, it can expose sensitive data stored in adjacent memory, potentially including error messages, internal state, or other confidential information. In multi-user or shared environments, attackers with local access could exploit this flaw to gather intelligence that may facilitate further attacks. The vulnerability does not affect system availability or integrity directly but could undermine trust in the software's error reporting mechanism. Since exploitation requires local access, the threat is mainly relevant in environments where untrusted users have some system access, such as shared servers, development machines, or compromised user accounts. The availability of a public exploit increases the likelihood of opportunistic attacks in such contexts. Organizations relying on FascinatedBox lily for critical applications should consider the risk of information leakage and potential indirect consequences.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 9 Mar 2026, 01:27 UTC

Technical details

References

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