CVE-2026-100723: patriksimek vm2 · Information Exposure
Affects patriksimek vm2Source CVE Database V5
Public exploit available · CVSS 6.9 Medium : upgrade to 3.12.2 as a priority.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- Exploitation
- Proof of concept is public or traded
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-10-01.
- Patch
- Available – fixed in 3.12.2
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:NExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 27 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE ID reserved
by VulnCheck
, 23 hours before disclosure
CVE published
on cve.org
, t = 0
CISA SSVC assessment
proof of concept public
, 4 days after disclosure
In Threat Radar
record ingested
, 29 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade patriksimek vm2 to 3.12.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| patriksimekvm2 | Affected
| Fixed in
|
npmvm2pkg:npm/vm2Other threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
vm2 before 3.12.2 does not apply its Buffer backing-store ownership invariant (byteOffset === 0 and buffer.byteLength === length) to Buffers returned from host builtin modules. When an application explicitly exposes Node's zlib module through NodeVM's builtin allowlist (require: { builtin: ['zlib'] }), zlib.deflateSync can return a Buffer backed by Node's shared small-buffer pool whose .buffer is the entire pool. Untrusted guest code can construct a full-width view of that ArrayBuffer (Buffer.from(result.buffer, 0, result.buffer.byteLength)) to read and modify bytes belonging to unrelated host buffers, disclosing and corrupting host-realm memory across the sandbox boundary.
References
- github.com/patriksimek/vm2/security/advisories/GHSA-489w-w794-jq94 (opens in a new tab)
- github.com/patriksimek/vm2/commit/4f2508abeb252aa86eb6761c78b3b000248fb089 (opens in a new tab)
- github.com/patriksimek/vm2/commit/5214b02ef13b82497fcb917b45320dfd014ffd09 (opens in a new tab)
- vulncheck.com/advisories/vm2-before-3.12.2-memory-disclosure-via-zlib-buffer-pool (opens in a new tab)