101arrowz fflate index.mjs unzipSync memory allocation

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-122146
StatePUBLISHED
AssignerVulDB
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-11-05 01:17:22 UTC
Updated2026-11-10 19:20:32 UTC
DescriptionA 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 uncontrolled memory allocation. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. It is suggested to update the configuration settings. The maintainer disputes this issue as a vulnerability. The library is a pure JavaScript decompressor that allocates memory proportional to the decompressed payload size, which is expected behavior. Excessive allocations simply throw a standard JavaScript RangeError or reach engine heap limits. Furthermore, because a low-level decompression library cannot distinguish between a maliciously crafted compression bomb and a legitimate file with a high compression ratio, the API explicitly provides a filter option allowing callers to restrict decompressed file sizes and prevent denial-of-service according to their application's requirements, as seen both in the documentation and noted in the reported issue.

Risk And Classification

Primary CVSS: v4.0 5.5 MEDIUM from [email protected]

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.002930000 probability, percentile 0.221430000 (date 2026-11-10)

Problem Types: CWE-400 | CWE-789 | CWE-789 Uncontrolled Memory Allocation | CWE-400 Resource Consumption

VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary5.5MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/C...
4.0CNADECLARED6.9MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
3.1[email protected]Primary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
3.1CNADECLARED5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:W/RC:C
3.0CNADECLARED5.3MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:W/RC:C
2.0[email protected]Secondary5AV:N/AC:L/Au:N/C:N/I:N/A:P
2.0CNADECLARED5AV:N/AC:L/Au:N/C:N/I:N/A:P/E:POC/RL:W/RC:C

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

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

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS v3.0 Breakdown

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

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:W/RC:C

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA 101arrowz Fflate affected 0.8.0 Not specified
CNA 101arrowz Fflate affected 0.8.1 Not specified
CNA 101arrowz Fflate affected 0.8.2 Not specified
CNA 101arrowz Fflate affected 0.8.3 Not specified

References

ReferenceSourceLinkTags
vuldb.com/vuln/431150/cti [email protected] vuldb.com
github.com/ictrun/java/issues/9 [email protected] github.com
vuldb.com/cve/CVE-2026-122146 [email protected] vuldb.com
vuldb.com/vuln/431150 [email protected] vuldb.com
vuldb.com/submit/1027352 [email protected] vuldb.com
github.com/101arrowz/fflate [email protected] github.com
github.com/101arrowz/fflate/blob/master/README.md [email protected] github.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: ictrun (VulDB User) (en)

CNA: VulDB CNA Team (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-11-04T00:00:00.000ZAdvisory disclosed
CNA2026-11-04T01:00:00.000ZVulDB entry created
CNA2026-11-10T19:12:21.000ZVulDB entry last update

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