CVE-2026-7768 json
@fastify/accepts-serializer vulnerable to Denial of Service via Unbounded Accept Header Cache Growth
published 2026-05-04 6 mo ago modified 2026-06-17 4 mo ago also GHSA-qxhc-wx3p-2wmg , EUVD-2026-27131
- cvss
- 7.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 21%
- public exploits
- 0
- none known
Summary
@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.
Patch / fix
- npm @fastify/accepts-serializer 6.0.4
- @fastify/accepts-serializer @fastify/accepts-serializer 6.0.4
CISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.28% chance of exploitation in the next 30 days, higher than 21% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| GitHub | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | @fastify/accepts-serializer | <6.0.4 |
6.0.4 |
Affected products
- @fastify/accepts-serializer @fastify/accepts-serializer
Classification
- Weakness
-
- CWE-770 Allocation of Resources Without Limits or Throttling
References
-
cna.openjsf.org
/security-advisories.html
web, vendor-advisory
-
github.com
/fastify/fastify-accepts-serializer/security/advisories/GHSA-qxhc-wx3p-2wmg
web, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-7768
advisory
-
github.com
/fastify/fastify-accepts-serializer
package
Sources
- CVE List CVE-2026-7768
- GitHub Advisory GHSA-qxhc-wx3p-2wmg
- NVD CVE-2026-7768
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.