Vulnerability · Published Nov 5, 2026 · Assigned by VulDB

CVE-2026-122146101arrowz fflate index.mjs unzipSync memory corruption

High 7.3

In plain English

A high-severity memory corruption in fflate from 101arrowz. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities).

Severity (CVSS 3.1)7.3High

Exploit odds (30 days)0.3%top 77.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

A weakness has been identified in 101arrowz fflate up to 0.8.3. This issue affects the function unzipSync of the file esm/index.mjs. This manipulation causes memory corruption. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.

Affected products (as reported)

Vendor	Product	Versions
101arrowz	fflate	0.8.00.8.10.8.20.8.3

Weakness: CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:C

References

VDB-431150 | 101arrowz fflate index.mjs unzipSync memory corruption vdb-entry, technical-description
VDB-431150 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
CVE-2026-122146 | CVE Analysis and Report third-party-advisory
Submit #1027352 | fflate <=0.8.3 Memory Corruption third-party-advisory
https://github.com/ictrun/java/issues/9 exploit, issue-tracking