How severe is CVE-2026-34752?

No CVSS score has been assigned to CVE-2026-34752 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-34752?

CVE-2026-34752 affects the following packages: Haraka (npm). Ecosystems affected: npm.

How do I fix CVE-2026-34752?

Update Haraka to 3.1.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34752 is resolved across your whole dependency graph.

How do I detect CVE-2026-34752 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Haraka. 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-2026-34752 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-2026-34752?

O3 pinpoints whether CVE-2026-34752 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-2026-34752 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-34752 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-2026-34752?

CVE-2026-34752 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-2026-34752 published, and has it been updated?

CVE-2026-34752 was published on April 2, 2026 and was last updated on August 5, 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-2026-34752

CVE-2026-34752 is a CWE-248 vulnerability in Haraka. O3 Security confirms whether CVE-2026-34752 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Haraka affected by DoS via `__proto__` email header

Also known asGHSA-xph3-r2jf-4vp3

Published

Apr 2, 2026

Updated

Aug 5, 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.

Harakanpm

24Kdownloads / week

Description

Haraka is a Node.js mail server. Prior to version 3.1.4, sending an email with proto: as a header name crashes the Haraka worker process. This issue has been patched in version 3.1.4.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`Haraka`	all versions	3.1.4

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Haraka. 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 Haraka to 3.1.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34752 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-2026-34752 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-2026-34752. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Haraka is a Node.js mail server. Prior to version 3.1.4, sending an email with __proto__: as a header name crashes the Haraka worker process. This issue has been patched in version 3.1.4.

O3 Security · Impact-Aware SCA

Is CVE-2026-34752 in your dependencies?

O3 detects CVE-2026-34752 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works