StableLib is a stable library of useful TypeScript and JavaScript code. Prior to 2.0.4, the @stablelib/cbor CBOR map decoding path creates ordinary JavaScript objects and assigns attacker-controlled keys with bracket assignment. A map key named __proto__ invokes the inherited prototype setter instead of creating an ordinary own property, allowing the decoded object's prototype to contain attacker-controlled authorization or feature-flag values. Downstream code that trusts normal property lookup or merges the decoded object can therefore make security-sensitive decisions using inherited attacker data. This issue is fixed in version 2.0.4.
CVE-2026-106448
HIGHPre-NVD 8.98.9
EchelonGraph scoreLOW confidence
This high-severity CVE scores 8.9 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: cna:github_m
8.9EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 8.9Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS v3
- 8.9
- EG Score
- 8.9HIGHlow confidence
- EG Risk
- 40EG Risk 40/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity89% × 45%Exploitation0% × 40%Automatability0% × 15%CISA SSVC: Track at every mission impact level.Action: A fix is available. Apply it within your standard update timelines. - EPSS PROB
- —
- EPSS %ILE
- —
- KEV
- Not listed
CISA SSVCTrack at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
October 6, 2026
Last Modified
October 7, 2026
Advisory Details (2)
Auto-updated Oct 6, 2026🔬 Proof of concept available. Patch available. Sources: github, github_commit.
github_commit
commit 0f153a63b755 (StableLib/stablelib)
Fix landed in StableLib/stablelib commit 0f153a63b755 — awaiting tagged release
https://github.com/StableLib/stablelib/commit/0f153a63b7552a0e8721f640984113e419015026githubMentions a patch (unverified)🟡 PoC Available
Prototype poisoning via `__proto__` map keys in CBOR decoding · Advisory · StableLib/stablelib · GitHub
https://github.com/StableLib/stablelib/security/advisories/GHSA-w48f-fwg7-ww6pAffected Packages
(1 across 1 ecosystem)
npm(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| @stablelib/cbor | — |
| — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 4× in last 7d / 4× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-10-07 17:22 UTCEG score recompute
- 2026-10-06 20:32 UTCEG score recompute
- 2026-10-06 19:52 UTCEG score recompute
- 2026-10-06 19:51 UTCMITRE cvelistV5first tracked
Related CVEs(same product + same CWE)
Frequently asked(4)
What is CVE-2026-106448?
CVE-2026-106448 is a high vulnerability published on October 6, 2026. StableLib is a stable library of useful TypeScript and JavaScript code. Prior to 2.0.4, the @stablelib/cbor CBOR map decoding path creates ordinary JavaScript objects and assigns attacker-controlled keys with bracket assignment. A map key named proto invokes the inherited prototype setter instead…
When was CVE-2026-106448 disclosed?
CVE-2026-106448 was first published on October 6, 2026, with the most recent update on October 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-106448?
CVE-2026-106448 has a CVSS base score of 8.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-106448?
A fix for CVE-2026-106448 is available: update to the fixed version the vendor names in its advisory.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-106448
Is Your Infrastructure Affected by CVE-2026-106448?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.