CVE-2026-7768

HIGH 7.5

@fastify/accepts-serializer vulnerable to Denial of Service via Unbounded Accept Header Cache Growth

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

@fastify/accepts-serializer cached serializer-selection results keyed by the request Accept header without a size limit or eviction policy. A remote unauthenticated client could send many distinct but matching Accept header variants to make the cache grow unbounded, eventually exhausting the Node.js heap and crashing the process. Versions <= 6.0.3 are affected. Update to 6.0.4 or later, which bounds the cache via an LRU with a default size of 100 entries, configurable through the new cacheSize plugin option.

CWE	CWE-770
Vendor	@fastify/accepts-serializer
Product	@fastify/accepts-serializer
Published	May 4, 2026
Last Updated	May 4, 2026

Stay Ahead of the Next One

Get instant alerts for @fastify/accepts-serializer @fastify/accepts-serializer

Be the first to know when new high vulnerabilities affecting @fastify/accepts-serializer @fastify/accepts-serializer are published — delivered to Slack, Telegram or Discord.

Get Free Alerts → Free · No credit card · 60 sec setup

CVSS v3 Breakdown

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

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

Affected Versions

@fastify/accepts-serializer / @fastify/accepts-serializer

0 < 6.0.4

References

NVD ↗ CVE.org ↗ EPSS Data ↗

cna.openjsf.org: https://cna.openjsf.org/security-advisories.html github.com: https://github.com/fastify/fastify-accepts-serializer/security/advisories/GHSA-qxhc-wx3p-2wmg

Credits

Yuki Matsuhashi Ulises Gascón Manuel Spigolon