CVE-2026-54428: Apache HttpComponents Core: HPackDecoder Unlimited Header List Size Before SETTINGS ACK
Apache Software Foundation · Apache HttpComponents Core
Vendor fix available · Affected: Apache Software Foundation Apache HttpComponents Core · Exploitation: not established
ExploitationNot established
Not in CISA KEV as of catalogue 2026.11.13 (13 Nov)
- In CISA KEV: not seen
- Exploited (reported): not seen
- Scanning observed: not seen
- Proof of concept public: not seen
- Not establishedNothing in the sources we check
Higher than 59% of scored CVEs
DescriptionNVD
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.
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Unlikely (under 1%). EPSS under 1%, or no score yet.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Published
- July 2026
Coverage1 article · 1 outlet
First in our coverage: SecurityOnline, 2 Jul.
- Apache HttpComponents Core Patches Two DoS Vulnerabilities in HTTP ParsersSecurityOnline · first in our coverage · mentions it in passing
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