CVE catalog
CVE-2026-45820
fflate through 0.8.2 is vulnerable to denial of service via an infinite loop in unzipSync(). A crafted ZIP archive with a central directory entry declaring compressed_size=0xFFFFFFFF (ZIP64 sentinel)
- Severity
- High · CVSS 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.28% · Oct 25, 2026
fflate through 0.8.2 is vulnerable to denial of service via an infinite loop in unzipSync(). A crafted ZIP archive with a central directory entry declaring compressed_size=0xFFFFFFFF (ZIP64 sentinel) but missing the required ZIP64 extra field tag 0x0001 causes z64e() to loop indefinitely due to out-of-bounds reads returning undefined, which coerces to 0, keeping the loop condition permanently true.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Cpe | fflate | Not reported | Not reported | unknown |
| Npm | fflate | Not reported | 0.8.3 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Npm | fflate | npm | Not reported | 0.8.3 | Not reported | GHSA-PX8P-9VWX-VF98 | Not reported |
OpenFactory catalog packages
No matching packages in this catalog.
Observed:
References
- [https://github.com/101arrowz/fflate/blob/f7873560ad229c22c4b23b06c6a3806ffde77569/src/index.ts#L2714]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-45820]
- [https://osv.dev/vulnerability/GHSA-px8p-9vwx-vf98]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45820.json]
- [https://wid.cert-bund.de/.well-known/csaf/white/2026/wid-sec-w-2026-3596.json]
- [https://www.npmjs.com/package/fflate]
[CERT-Bund public advisories] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]