adm-zip 0.6.0 Decompression Bomb Guard Bypass via getDataAsync()

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

adm-zip 0.6.0 contains a decompression bomb protection bypass that allows attackers to evade the maxOutputLength guard by targeting the asynchronous getDataAsync() path in methods/inflater.js. Attackers can craft ZIP entries with falsified small declared sizes and high-ratio DEFLATE payloads to exhaust memory in applications reading entries asynchronously.

Source published

21 Oct 2026 00:37:04 UTC

Source modified

27 Oct 2026 21:54:59 UTC

Observed here

27 Oct 2026 22:45:55 UTC

Source terms

CVE Program Terms of Use

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CVSS 4.0 · 6.9 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

CVSS 3.1 · 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

adm-zip 0.6.0 contains a decompression bomb protection bypass that allows attackers to evade the maxOutputLength guard by targeting the asynchronous getDataAsync() path in methods/inflater.js. Attackers can craft ZIP entries with falsified small declared sizes and high-ratio DEFLATE payloads to exhaust memory in applications reading entries asynchronously.

Source published

Oct 21, 2026, 12:37:04 AM (timezone not stated)

Source modified

Oct 27, 2026, 9:54:59 PM (timezone not stated)

Observed here

30 Oct 2026 01:58:34 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 4.0 · 6.9 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

adm-zip 0.6.0 contains a decompression bomb protection bypass that allows attackers to evade the maxOutputLength guard by targeting the asynchronous getDataAsync() path in methods/inflater.js. Attackers can craft ZIP entries with falsified small declared sizes and high-ratio DEFLATE payloads to exhaust memory in applications reading entries asynchronously.

Source published

21 Oct 2026 01:17:36 UTC

Source modified

27 Oct 2026 22:17:25 UTC

Observed here

29 Oct 2026 06:48:04 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 6.9 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:X/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 3.1 · [email protected] · Secondary · 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

### Summary adm-zip enforces a `maxOutputLength` guard against decompression bombs on its synchronous `getData()` path, but the equivalent asynchronous `getDataAsync()` path does not enforce it — it accumulates and returns the entire decompressed output regardless of the entry's declared size. An application that checks an entry's declared size before deciding to process it, then reads the entry via `getDataAsync()` (a completely ordinary, often-recommended choice for I/O in Node.js), gets none of the protection it believes it has. ### Details - `methods/inflater.js:3-10` passes `{maxOutputLength: expectedLength}` to `inflateRawSync`, which Node enforces. - `methods/inflater.js:12-31` passes the same option to `createInflateRaw` but never enforces it on the streaming path — it just accumulates every chunk and allocates a final Buffer of whatever size resulted. ### PoC ```js const AdmZip = require('adm-zip'); const zip = new AdmZip(); zip.addFile('p', Buffer.alloc(64 * 1024 * 1024, 0x41)); // 64 MiB const raw = Buffer.from(zip.toBuffer()); // patch the local + central declared uncompressed size to 1 byte raw.writeUInt32LE(1, localHeaderSizeOffset); raw.writeUInt32LE(1, centralHeaderSizeOffset); const entry = new AdmZip(raw).getEntry('p'); entry.getData(); // throws: ERR_BUFFER_TOO_LARGE: Cannot create a Buffer larger than 1 bytes entry.getDataAsync((data, error) => { ... }); // returns the full 67,108,864-byte buffer, error is undefined ``` ### Impact An application that validates a declared size before reading an entry, then uses the async API, gets no protection against a high-ratio DEFLATE payload. Repeated or larger requests could contribute to memory exhaustion.

Source published

29 Sep 2026 23:10:32 UTC

Source modified

21 Oct 2026 10:57:29 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Publisher rating · MODERATE