How severe is CVE-2020-26309?

No CVSS score has been assigned to CVE-2020-26309 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2020-26309?

CVE-2020-26309 affects the following packages: nope-validator (npm). Ecosystems affected: npm.

How do I fix CVE-2020-26309?

Update nope-validator to 0.12.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-26309 is resolved across your whole dependency graph.

How do I detect CVE-2020-26309 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nope-validator, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2020-26309 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2020-26309 actively exploited in the wild?

No public exploit code has been indexed for CVE-2020-26309 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2020-26309?

CVE-2020-26309 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 39th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2020-26309?

CVE-2020-26309 is classified as CWE-1333 (CWE-1333). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2020-26309 published, and has it been updated?

CVE-2020-26309 was published on October 26, 2024 and was last updated on October 20, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2020-26309 — nope-validator

Fix: ftonato/nope-validator@4564b74

CVE-2020-26309 is a CWE-1333 vulnerability in nope-validator. A fix is available for nope-validator — see the affected versions and patch details below.

nope-validator Regular Expression Denial of Service vulnerability

Also known asGHSA-3phv-83cj-p8p7

Published

Oct 26, 2024

Updated

Oct 20, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2020-26309.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs39th percentile — riskier than 39% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

2other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

nope-validatornpm

2Kdownloads / week

Description

Validate.js provides a declarative way of validating javascript objects. Versions 0.11.3 and prior contain one or more regular expressions that are vulnerable to Regular Expression Denial of Service (ReDoS). As of time of publication, it is unknown if any patches are available.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`nope-validator`	all versions	0.12.1`npm install nope-validator@0.12.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for nope-validator, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update nope-validator to 0.12.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-26309 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-26309 in your dependencies?

Find it across npm, including transitive dependencies.

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