How severe is GHSA-4rhm-m2fp-hx7q?

GHSA-4rhm-m2fp-hx7q has a CVSS score of 4/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by GHSA-4rhm-m2fp-hx7q?

GHSA-4rhm-m2fp-hx7q affects the following packages: october/backend (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-4rhm-m2fp-hx7q?

Update october/backend to 1.0.466 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4rhm-m2fp-hx7q is resolved across your whole dependency graph.

How do I detect GHSA-4rhm-m2fp-hx7q in my Packagist dependencies?

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

How do I mitigate GHSA-4rhm-m2fp-hx7q if there is no patch (or I can't update yet)?

Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Is GHSA-4rhm-m2fp-hx7q actively exploited in the wild?

No public exploit code has been indexed for GHSA-4rhm-m2fp-hx7q 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 GHSA-4rhm-m2fp-hx7q?

GHSA-4rhm-m2fp-hx7q has an EPSS (Exploit Prediction Scoring System) score of 1.0%, placing it in the 63th 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 GHSA-4rhm-m2fp-hx7q?

GHSA-4rhm-m2fp-hx7q is classified as CWE-77 (CWE-77). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-4rhm-m2fp-hx7q published, and has it been updated?

GHSA-4rhm-m2fp-hx7q was published on June 3, 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.

🐘

🐘 Packagist

Not in CISA KEV

MEDIUM severity

Potential CSV Injection vector in OctoberCMSGHSA-4rhm-m2fp-hx7q

MEDIUMFix: octobercms/library@c84bf03

GHSA-4rhm-m2fp-hx7q is a medium-severity (CVSS 4) CWE-77 vulnerability in october/backend. A fix is available for october/backend — see the affected versions and patch details below.

Also known asCVE-2020-5299

Published

Jun 3, 2020

Updated

Jul 8, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.0%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs63th percentile — riskier than 63% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

🐘october/backend

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

Description

Impact

Any users with the ability to modify any data that could eventually be exported as a CSV file from the ImportExportController could potentially introduce a CSV injection into the data to cause the generated CSV export file to be malicious. This requires attackers to achieve the following before a successful attack can be completed:

Have found a vulnerability in the victim's spreadsheet software of choice.
Control data that would potentially be exported through the ImportExportController by a theoretical victim.
Convince the victim to export above data as a CSV and run it in vulnerable spreadsheet software while also bypassing any sanity checks by said software.

Patches

Issue has been patched in Build 466 (v1.0.466).

Workarounds

Apply https://github.com/octobercms/library/commit/c84bf03f506052c848f2fddc05f24be631427a1a & https://github.com/octobercms/october/commit/802d8c8e09a2b342649393edb6d3ceb958851484 to your installation manually if unable to upgrade to Build 466.

References

Reported by @chrisvidal initially & Sivanesh Ashok later.

For more information

If you have any questions or comments about this advisory:

Email us at [email protected]

Threat assessment:

Given the number of hoops that a potential attacker would have to jump through, this vulnerability really boils down to the possibility of abusing the trust that a user may have in the export functionality of the project. Thus, this has been rated low severity as it requires vulnerabilities to also exist in other software used by any potential victims as well as successful social engineering attacks.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`october/backend`	≥ 1.0.319&&< 1.0.466	1.0.466`composer require october/backend:^1.0.466`

Affected Products

1 product · 1 configurations

Application

octoberoctobercms

≥ 1.0.319 && < 1.0.466

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for october/backend, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update october/backend to 1.0.466 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4rhm-m2fp-hx7q is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.

Frequently Asked Questions

### Impact Any users with the ability to modify any data that could eventually be exported as a CSV file from the `ImportExportController` could potentially introduce a CSV injection into the data to cause the generated CSV export file to be malicious. This requires attackers to achieve the following before a successful attack can be completed: 1. Have found a vulnerability in the victim's spreadsheet software of choice. 2. Control data that would potentially be exported through the `ImportExportController` by a theoretical victim. 3. Convince the victim to export above data as a CSV and run