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Node.js zlib CVE-2026-58045

| EUVDEUVD-2026-52562 MEDIUM
Uncontrolled Resource Consumption (CWE-400)
6.2
CVSS 3.0 · Vendor
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Severity by source

Vendor (CNA) PRIMARY
6.2 MEDIUM
AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
vuln.today AI
6.2 MEDIUM

Local attack vector confirmed by Node.js team assignment; no confidentiality or integrity impact - only availability loss via process crash.

3.1 AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
4.0 AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
SUSE
MEDIUM
qualitative
Red Hat
6.2 MEDIUM
qualitative

Primary rating from Vendor (CNA).

CVSS VectorVendor

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

Lifecycle Timeline

5
Source Code Evidence Fetched
Aug 04, 2026 - 01:24 vuln.today
Analysis Generated
Aug 04, 2026 - 01:24 vuln.today
CVSS changed
Aug 04, 2026 - 01:22 NVD
6.2 (MEDIUM)
CVE Published
Jul 29, 2026 - 14:02 github-releases
MEDIUM 6.2
CVE Published
Jul 29, 2026 - 14:02 github-releases
UNKNOWN (no severity yet)

Description PRE-NVD

Disclosed via GitHub release of nodejs/node. NVD scoring and full description are pending.

AnalysisAI

Out-of-bounds write buffer handling in the Node.js built-in zlib module (v26.x prior to v26.5.1) fails to throw an exception when a write buffer exceeds valid bounds, enabling a local denial-of-service via process crash or uncontrolled resource consumption. The Node.js security team rated this Medium severity (CVSS 6.2, AV:L) and shipped a fix in v26.5.1 on 2026-07-29 as part of a broader security release addressing ten CVEs. No public exploit code and no CISA KEV listing have been identified at time of analysis.

Technical ContextAI

The vulnerability resides in Node.js's built-in zlib module, which wraps the native zlib C library to provide deflate, inflate, gzip, brotli, and related compression stream operations used widely across the Node.js ecosystem. CWE-400 (Uncontrolled Resource Consumption) characterizes the root cause: the write path did not validate whether a supplied buffer was within valid bounds before proceeding, meaning an oversized or malformed buffer could drive resource exhaustion or trigger undefined behavior leading to a process crash. The fix by RafaelGSS (commit af0bf96877 series, nodejs-private/node-private) introduces an explicit bounds check that throws a catchable JavaScript error, converting an unhandled fault into a recoverable exception. No explicit CPE string was provided in the input, but the affected artifact is the node binary for the Current release line (v26.x) prior to v26.5.1.

RemediationAI

Upgrade Node.js Current to v26.5.1 or later, as released 2026-07-29 and documented at https://github.com/nodejs/node/releases/tag/v26.5.1 and https://nodejs.org/en/blog/vulnerability/july-2026-security-releases. No explicit workarounds are documented in the available data. As a compensating control prior to patching, applications should validate buffer sizes before invoking zlib APIs (e.g., zlib.deflate, zlib.createGzip, zlib.createInflate), enforcing maximum input sizes at the application boundary and rejecting buffers that exceed expected limits - this adds validation overhead but reduces the attack surface. Check nodejs.org for corresponding patches to active LTS lines (v20.x, v22.x) if those versions are in use.

Vendor StatusVendor

SUSE

Severity: Moderate
Product Status
openSUSE Tumbleweed Fixed
SUSE Linux Enterprise Server 15 SP6-LTSS Affected
SUSE Linux Enterprise Server 15 SP6-LTSS Affected
SUSE Linux Enterprise Server for SAP Applications 15 SP6 Affected
SUSE Linux Enterprise High Performance Computing 12 Affected

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CVE-2026-58045 vulnerability details – vuln.today

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