Detections
Analytics

SCA: security update for org.http4s:http4s-ember-core_2.12, org.http4s:http4s-ember-core_2.13, org.http4s:http4s-ember-core_3 (GHSA-vmm3-xgcx-67hm)

high Tenable Cloud Security Plugin ID 446364

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - Http4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, an unauthenticated HTTP/2
 peer can cause an out-of-memory denial of service in the Ember backend with HTTP/2 enabled. The Hpack
 wrapper in ember-core/shared/src/main/scala/org/http4s/ember/core/h2/Hpack.scala concatenates HEADERS and
 CONTINUATION frame fragments and decodes them into a single List, but maxHeaderSize accounting does not
 include indexed headers or HPACK per-header overhead. A small compressed header block can therefore expand
 into a much larger decoded representation that remains in memory for processing. Servers exposed to
 untrusted HTTP/2 traffic and clients directed to an untrusted HTTP/2 server are affected, and concurrent
 malicious connections can exhaust the process heap. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
 (CVE-2026-54556)

Solution

Update the org.http4s:http4s-ember-core_2.12 library and its related packages to version 0.23.35 or later.

See Also

https://github.com/advisories/GHSA-vmm3-xgcx-67hm

Plugin Details

Severity: High

ID: 446364

Version: Revision 1.1

Type: Local

Family: SCA Checks

Published: 8/26/2026

Updated: 8/26/2026

Risk Information

Vendor

Vendor Severity: High

CVSS v2

Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.2

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2026-54556

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 8.2

Threat Score: 4.6

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 8/26/2026

Vulnerability Publication Date: 8/26/2026

Reference Information

CVE: CVE-2026-54556

cwe: CWE-409