CVE-2026-7768

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

HIGH
7.5
CVSS Score
Published: May 4, 2026 at 07:14 PM UTC
Updated: June 17, 2026 at 11:02 AM UTC
2 products affected across 1 vendorFastify /accepts SerializerAccepts Serializer

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Severity
HIGH7.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

@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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 6.0.4
Vendor states this is fixed in 6.0.4 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHopenjs
Vector?

Quick Info

StatusANALYZED
CWE
CWE-770

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