CVE-2026-54428
Allocation of resources without limits or throttling in the HTTP/2 HPACK decoder in Apache HttpComponents Core (5.4.2 and earlier, 5.5-beta1 and earlier) allows an remote attacker to cause a denial of service through memory exhaustion by sending…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.87%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Allocation of resources without limits or throttling in the HTTP/2 HPACK decoder in Apache HttpComponents Core (5.4.2 and earlier, 5.5-beta1 and earlier) allows an remote attacker to cause a denial of service through memory exhaustion by sending oversized compressed header blocks before the HTTP/2 SETTINGS acknowledgement causes the configured header list size limit to be applied.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.87% probability · 57th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-400, CWE-770
- Affected
- apache/httpcomponents core
- Source
- security@apache.org
References
- https://lists.apache.org/thread/5zjp8vczvxq19pw2rvhs21q446bhl0sdMitigation, Vendor Advisory
- http://www.openwall.com/lists/oss-security/2026/07/01/3Mitigation, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.