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GHSA-76v6-f83q-pxvh

Duplicate Advisory: Hackney has an Allocation of Resources Without Limits or Throttling vulnerabilit

High Withdrawn Jun 30, 2026 Hex
Severity
0.0 / 10
High · CVSS 4.0
Exploit chance (EPSS)
—
No score published
Known exploited
No
Not in CISA's catalog
Weakness
CWE-400 Uncontrolled Resource Consumption
Fix
4.0.1
Upgrade hackney to this version or later

Description

Duplicate Advisory

This advisory has been withdrawn because it is a duplicate of GHSA-jq4m-q6p2-8gwc. This link is maintained to preserve external references.

Original Description

Allocation of Resources Without Limits or Throttling vulnerability in benoitc hackney allows Flooding. hackney_h3:await_response_loop/6 accumulates the HTTP/3 response body in memory without any size cap. The after Timeout clause is a per-message inactivity timer that resets on every received chunk, housekeeping message, or settings frame — it is not a wall-clock deadline. A malicious HTTP/3 server that emits one small chunk every Timeout - 1 ms with Fin = false and never sends a final frame keeps the loop alive indefinitely while the accumulation buffer grows linearly without bound, eventually exhausting the BEAM process heap and causing an out-of-memory condition.

This issue affects hackney: from 2.0.0 before 4.0.1.

Affected versions

Hex

PackageVulnerableFixed in
hackney
>= 2.0.0, < 4.0.1
4.0.1

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

hackney Hex → 4.0.1

mix
{:hackney, "~> 4.0.1"} # then: mix deps.update hackney

Severity breakdown

CVSS 4.0 0.0

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

Attack vector
Network
Attack complexity
Low
Attack requirements
Present
Privileges required
None
User interaction
None
Confidentiality (vulnerable system)
None
Integrity (vulnerable system)
None
Availability (vulnerable system)
High
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None

CVSS 3.1 7.5

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Weakness

CWE-400: Uncontrolled Resource Consumption

The product does not properly control the allocation and maintenance of a limited resource.

How to prevent it
  • Architecture and Design: Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place. The login application should be protected against DoS attacks as much as possible. Limiting the database access, perhaps by caching result sets, can help minimize the resources expended. To further limit the potential for a DoS attack, consider tracking the rate of requests received from users and blocking requests that exceed a defined rate threshold.
  • Architecture and Design: Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed. The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question. The second solution is simply difficult to effectively institute -- and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.
  • Architecture and Design: Ensure that protocols have specific limits of scale placed on them.
  • Implementation: Ensure that all failures in resource allocation place the system into a safe posture.

References

Timeline

  1. Published
  2. Withdrawn
  3. Last updated by the source
AdvisorySeverityWhy it's related
EEF-CVE-2026-97200
Unbounded response body buffering and decompression in hackney
Not rated yet Also affects hackney
EEF-CVE-2026-115693
Custom cacerts or cacertfile do not restrict trust to the pinned CA in hackney
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EEF-CVE-2026-113440
HTTP/1.1 and HTTP/2 redirects resend basic_auth and cookie to a different scheme or port in hackney
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EEF-CVE-2026-115700
SSRF allowlist bypass via percent-encoded bracketed IPv6 or trailing-dot IP literal in hackney
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EEF-CVE-2026-112880
CRLF injection in Proxy-Authorization header built from proxy_auth_fun in hackney
Not rated yet Also affects hackney
EEF-CVE-2026-47073
Unbounded memory consumption in WebSocket client in hackney
High Also affects hackney
EEF-CVE-2026-47067
Atom table exhaustion via unrecognized URL schemes in hackney
High Also affects hackney
EEF-CVE-2026-47072
CRLF injection in WebSocket upgrade request in hackney
High Also affects hackney
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