How severe is CVE-2020-8135?

CVE-2020-8135 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-8135?

CVE-2020-8135 affects the following packages: @uppy/companion (npm). Ecosystems affected: npm.

How do I fix CVE-2020-8135?

Update @uppy/companion to 1.9.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-8135 is resolved across your whole dependency graph.

How do I detect CVE-2020-8135 in my npm dependencies?

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

How do I mitigate CVE-2020-8135 if there is no patch (or I can't update yet)?

Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Is CVE-2020-8135 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2020-8135, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-8135?

CVE-2020-8135 has an EPSS (Exploit Prediction Scoring System) score of 1.3%, placing it in the 70th 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-2020-8135?

CVE-2020-8135 is classified as Server-Side Request Forgery (SSRF) (CWE-918). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2020-8135 published, and has it been updated?

CVE-2020-8135 was published on March 20, 2020 and was last updated on July 8, 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

CRITICAL severity

CVE-2020-8135 — @uppy/companion

CRITICAL

CVE-2020-8135 is a critical-severity (CVSS 9.8) Server-Side Request Forgery (SSRF) vulnerability in @uppy/companion. 1 public exploit reference exists, so weaponization risk is real. A fix is available for @uppy/companion — see the affected versions and patch details below.

Server-Side Request Forgery in @uppy/companion

Also known asGHSA-mm7r-265w-jv6f

Published

Mar 20, 2020

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Oct 2, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs70th percentile — riskier than 70% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2020-8135 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

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.

8other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@uppy/companionnpm

50Kdownloads / week

Description

Versions of @uppy/companion prior to 1.9.3 are vulnerable to Server-Side Request Forgery (SSRF). The get route passes the user-controlled variable req.body.url to a GET request without sanitizing the value. This allows attackers to inject arbitrary URLs and make GET requests on behalf of the server.

Recommendation

Upgrade to version 1.9.3 or later.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@uppy/companion`	all versions	1.9.3`npm install @uppy/companion@1.9.3`

Affected Products

1 product · 1 configurations

Application

uppyuppy

< 1.9.3

range

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

The uppy npm package < 1.9.3 is vulnerable to a Server-Side Request Forg…

hackerone.comNVDMar 2020

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @uppy/companion, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @uppy/companion to 1.9.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-8135 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Frequently Asked Questions

Versions of `@uppy/companion` prior to 1.9.3 are vulnerable to Server-Side Request Forgery (SSRF). The `get` route passes the user-controlled variable `req.body.url` to a GET request without sanitizing the value. This allows attackers to inject arbitrary URLs and make GET requests on behalf of the server. ## Recommendation Upgrade to version 1.9.3 or later.

O3 Security · Impact-Aware SCA

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CVSS Score

9.8/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Raw vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE Classification

CWE-918Server-Side Request Forgery (SSRF)

Weaponization

No known public exploit tooling found.

Timeline

Disclosed

Mar 20, 2020

First exploit

Mar 24, 2020

4 days after disclosure — rapid exploitation

Last updated

Jul 8, 2026

Identifiers

CVE-2020-8135

GHSA-mm7r-265w-jv6f

References

Advisorynvd.nist.gov Fixhackerone.com Webnpmjs.com

Related vulnerabilities

Also affects @uppy/companion

This CVE is critical severity — higher than any of the other 3 CVEs affecting @uppy/companion (highest there: high).

CVE-2022-0528CVE-2022-0086CVE-2020-8205

Same weakness: CWE-918

This CVE is critical severity — higher than any of the other 5 CVEs with CWE-918 (highest there: high).

GHSA-39wr-7q6h-cf68GHSA-jgh3-fggc-mcpmCVE-2026-85732CVE-2026-59823CVE-2026-61793Browse all CWE-918

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedJul 8, 2026

CVE-2020-8135 — @uppy/companion

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Recommendation

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2020-8135 in your dependencies?