How severe is CVE-2020-7791?

CVE-2020-7791 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-7791?

CVE-2020-7791 affects the following packages: i18n (NuGet). Ecosystems affected: NuGet.

How do I fix CVE-2020-7791?

Update i18n to 2.1.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-7791 is resolved across your whole dependency graph.

How do I detect CVE-2020-7791 in my NuGet dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for i18n, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2020-7791 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is CVE-2020-7791 actively exploited in the wild?

No public exploit code has been indexed for CVE-2020-7791 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-2020-7791?

CVE-2020-7791 has an EPSS (Exploit Prediction Scoring System) score of 3.0%, placing it in the 87th 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.

When was CVE-2020-7791 published, and has it been updated?

CVE-2020-7791 was published on December 11, 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.

.NET

.NET NuGet

Not in CISA KEV

HIGH severity

CVE-2020-7791 — i18n

HIGHFix: turquoiseowl/i18n@c418e33

CVE-2020-7791 is a high-severity (CVSS 7.5) vulnerability in i18n. A fix is available for i18n — see the affected versions and patch details below.

Denial of Service in i18n

Also known asGHSA-hfvc-g252-rp4gSNYK-DOTNET-I18N-1050179

Published

Dec 11, 2020

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

3.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs87th percentile — riskier than 87% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2020-7791 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

.NETi18n

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects NuGet packages — download data is not available via public APIs for these ecosystems.

Description

This affects the package i18n before version 2.1.15. Vulnerability arises out of insufficient handling of erroneous language tags in src/i18n/Concrete/TextLocalizer.cs and src/i18n/LocalizedApplication.cs.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
.NETNuGet	`i18n`	all versions	2.1.15`dotnet add package i18n --version 2.1.15`

Affected Products

1 product · 1 configurations

Application

i18ni18n_project

< 2.1.15

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for i18n, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update i18n to 2.1.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-7791 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

Is CVE-2020-7791 in your dependencies?

Find it across NuGet, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

7.5/10CVSS v3 base

Vector breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Raw vector

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

Weaponization

No known public exploit tooling found.

OpenSSF Scorecard

Package health score

i18n

2.7/10

Maintained0/10

Code-Review1/10

Branch-Protection0/10

Assessed Oct 5, 2026

Timeline

Disclosed

Dec 11, 2020

Last updated

Jul 8, 2026

Identifiers

CVE-2020-7791

GHSA-hfvc-g252-rp4g

SNYK-DOTNET-I18N-1050179

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedJul 8, 2026

CVE-2020-7791 — i18n

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2020-7791 in your dependencies?