CVE-2021-32566 json
Specific sequence of HTTP/2 frames can cause ATS to crash
published 2021-06-30 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-19408
- cvss
- 7.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.4%
- EPSS 2.4% chance of exploitation in 30 days, percentile 84%
- public exploits
- 0
- none known
Summary
Improper Input Validation vulnerability in HTTP/2 of Apache Traffic Server allows an attacker to DOS the server. This issue affects Apache Traffic Server 7.0.0 to 7.1.12, 8.0.0 to 8.1.1, 9.0.0 to 9.0.1.
Patch / fix
- trafficserver Debian 12 8.1.1+ds-1.1
debian advisories DEBIAN-CVE-2021-32566
Exploit prediction
2.45% chance of exploitation in the next 30 days, higher than 84% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 2.0 | 5.0 | AV:N/AC:L/Au:N/C:N/I:N/A:P |
Affected products
- Apache Software Foundation Apache Traffic Server
Classification
- Weakness
-
- CWE-20 Improper Input Validation
References
-
debian.org
/security/2021/dsa-4957
vendor-advisory, third-party-advisory
-
lists.apache.org
/thread.html/ra1a41ff92a70d25bf576d7da2590575e8ff430393a3f4a0c34de4277%40%3Cusers.trafficserver.apache.org%3E
mailing-list, vendor-advisory
Sources
- CVE List CVE-2021-32566
- NVD CVE-2021-32566
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.