How severe is CVE-2025-48997?

No CVSS score has been assigned to CVE-2025-48997 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-48997?

CVE-2025-48997 affects the following packages: multer (npm). Ecosystems affected: npm.

How do I fix CVE-2025-48997?

Update multer to 2.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-48997 is resolved across your whole dependency graph.

How do I detect CVE-2025-48997 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for multer. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2025-48997 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.

How does O3 Security protect against CVE-2025-48997?

O3 pinpoints whether CVE-2025-48997 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2025-48997 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-48997 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 type of vulnerability is CVE-2025-48997?

CVE-2025-48997 is classified as CWE-248 (CWE-248). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2025-48997 published, and has it been updated?

CVE-2025-48997 was published on June 3, 2025 and was last updated on July 16, 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

CVE-2025-48997

CVE-2025-48997 is a CWE-248 vulnerability in multer. O3 Security confirms whether CVE-2025-48997 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Multer vulnerable to Denial of Service via unhandled exception

Also known asGHSA-g5hg-p3ph-g8qg

Published

Jun 3, 2025

Updated

Jul 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Blast Radius

1 pkg affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

multernpm

20.5Mdownloads / week

Description

Multer is a node.js middleware for handling multipart/form-data. A vulnerability that is present starting in version 1.4.4-lts.1 and prior to version 2.0.1 allows an attacker to trigger a Denial of Service (DoS) by sending an upload file request with an empty string field name. This request causes an unhandled exception, leading to a crash of the process. Users should upgrade to 2.0.1 to receive a patch. No known workarounds are available.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`multer`	≥ 1.4.4-lts.1&&< 2.0.1	2.0.1

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for multer. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update multer to 2.0.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-48997 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.
How O3 protects you
O3 pinpoints whether CVE-2025-48997 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2025-48997. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Multer is a node.js middleware for handling `multipart/form-data`. A vulnerability that is present starting in version 1.4.4-lts.1 and prior to version 2.0.1 allows an attacker to trigger a Denial of Service (DoS) by sending an upload file request with an empty string field name. This request causes an unhandled exception, leading to a crash of the process. Users should upgrade to `2.0.1` to receive a patch. No known workarounds are available.

O3 Security · Impact-Aware SCA

Is CVE-2025-48997 in your dependencies?

O3 detects CVE-2025-48997 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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