CVE-2026-115895

HIGHPre-NVD 8.88.8
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

This high-severity CVE scores 8.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (30th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 3 sources updated this week

Also known asEUVD-2026-109189 (ENISA EUVD) · GHSA-834v-8h66-3h79 (GitHub Security Advisories)Source: ENISA EUVD

8.8EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. From 17.0.0 until 21.0.4, packages/happy-dom/src/module/ECMAScriptModuleCompiler.ts accepts a named ESM import alias without validating that it is a JavaScript binding identifier before inserting it into a generated destructuring binding. With enableJavaScriptEvaluation enabled, attacker-controlled HTML or module source can use an invalid alias that becomes a valid default initializer after compilation, causing the generated JavaScript to execute in the Node.js host process. The demonstrated reachable path uses a JSON module import attribute, which prevents the malicious alias from being emitted again in a later ESM circular-import assignment and keeps the generated function syntactically valid. This incomplete fix for CVE-2026-33943 is a distinct residual path because the earlier remediation validated the local export importName path but not the named-import alias. This issue is fixed in version 21.0.4.

CVSS v3
8.8
EG Score
8.8HIGHmedium confidence
EG Risk
40
EG Risk 40/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity88% × 45%
Impact severity (EG Severity): CVSS 8.8 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.4%
EPSS %ILE
30th
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (8.8): severity, escalated by confirmed exploitation. This CVE's 8.8 is its impact severity (EG Severity), not escalated.

EG Severity
8.8 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-26). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

October 23, 2026

Last Modified

October 26, 2026

Advisory Details (4)

Auto-updated Oct 23, 2026
🔬 Proof of concept available. Patch available. Sources: github, github_pr, github_commit, github_release.
GitHub release Patch Available

v21.0.4

Patch available: capricorn86/happy-dom v21.0.4

https://github.com/capricorn86/happy-dom/releases/tag/v21.0.4
GitHub commit Patch Available

commit fd163520b74d (capricorn86/happy-dom)

Patch available: capricorn86/happy-dom v21.0.4 (contains commit fd163520b74d)

https://github.com/capricorn86/happy-dom/commit/fd163520b74d9fa146be91f7b4e4f46d6cccbe13
GitHub pull request Patch Available

fix: Fixed a code injection vulnerability in the ESM compiler

Patch available: capricorn86/happy-dom v21.0.4 (PR #2537 merged 2026-10-20)

https://github.com/capricorn86/happy-dom/pull/2537
GitHub advisoryMentions a patch (unverified)🟡 PoC Available

Incomplete fix for CVE-2026-33943: unsanitized import alias leads to host code execution · Advisory · capricorn86/happy-dom · GitHub

https://github.com/capricorn86/happy-dom/security/advisories/GHSA-834v-8h66-3h79

Vendor Advisories for CVE-2026-115895(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFix by version rangeDependents
happy-dom—
  • 17.0.0 up to 21.0.4: fixed in 21.0.4
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 8× in last 7d / 8× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. 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. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

  1. 2026-10-26 18:49 UTCEG score recompute
  2. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  3. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.4% · 30th percentile
  4. 2026-10-25 14:50 UTCEG score recompute
  5. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  6. 2026-10-23 22:29 UTCEG score recompute
  7. 2026-10-23 21:35 UTCEG score recomputeFirst assessed: 8.8 HIGH
  8. 2026-10-23 21:34 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-115895?
CVE-2026-115895 is a high-severity vulnerability; its CVE record was published on October 23, 2026. Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. From 17.0.0 until 21.0.4, packages/happy-dom/src/module/ECMAScriptModuleCompiler.ts accepts a named ESM import alias without validating that it is a JavaScript binding identifier before inserting it into…
When was the CVE record for CVE-2026-115895 published?
The CVE record for CVE-2026-115895 was published on October 23, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of October 26, 2026; the record at its source may have been updated since.
Is CVE-2026-115895 actively exploited?
CVE-2026-115895 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (30th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-115895?
CVE-2026-115895 has a CVSS base score of 8.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-115895?
A fix for CVE-2026-115895 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-115895 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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