CVE-2026-2662
Published: 18 February 2026
Summary
CVE-2026-2662 is a medium-severity Improper Restriction of Operations within the Bounds of a Memory Buffer (CWE-119) vulnerability in Lily-Lang Lily. Its CVSS base score is 4.8 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 1.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 AC-6 (Least Privilege) and CM-7 (Least Functionality).
Deeper analysis
CVE-2026-2662 is an out-of-bounds read vulnerability in FascinatedBox lily versions up to 2.3, specifically affecting the count_transforms function in the src/lily_emitter.c file. This flaw, associated with CWE-119, CWE-125, and CWE-787, has a CVSS v3.1 base score of 3.3 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L), indicating low severity with primarily availability impact.
The vulnerability requires local access with low privileges to exploit, involving low-complexity manipulation that triggers the out-of-bounds read. Successful exploitation results in limited denial-of-service effects, such as application crashes, with no confidentiality or integrity impacts.
Advisories note that the project was informed early via GitHub issue #381 but has not responded, and no patches are available. A public proof-of-concept exploit is available at https://github.com/oneafter/0122/blob/main/i381/repro.lily, which could facilitate attacks. Additional details are in the project repository at https://github.com/FascinatedBox/lily/issues/381 and VulDB entries at https://vuldb.com/?ctiid.346460 and https://vuldb.com/?id.346460.
The exploit has been made publicly available, increasing the risk of targeted local attacks despite the lack of project response.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-7640
Vulnerability details
A weakness has been identified in FascinatedBox lily up to 2.3. This vulnerability affects the function count_transforms of the file src/lily_emitter.c. This manipulation causes out-of-bounds read. The attack can only be executed locally. The exploit has been made available to…
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the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
OOB read in lily interpreter triggers local application crash (DoS); directly maps to exploitation-based endpoint DoS with public PoC file execution.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Restricting user privileges to the minimum required directly limits the ability of a local attacker to execute the vulnerable count_transforms path in lily.
Hardware or OS memory-protection mechanisms (ASLR, non-executable pages, bounds enforcement) reduce the likelihood and impact of the out-of-bounds read in src/lily_emitter.c.
Disabling or removing the lily interpreter when not explicitly required eliminates the attack surface exposed by the unpatched flaw.