CVE-2026-59246
Published:July 14, 2026
Updated:August 04, 2026
Allocation of resources without limits vulnerability in elixir-mint mint allows a remote HTTP/2 server to exhaust memory on the client host and cause a denial of service.
The Mint.HTTP2.handle_continuation/3 function in lib/mint/http2.ex accumulates the header-block fragment carried by each HTTP/2 CONTINUATION frame into a growing conn.headers_being_processed nesting, one level deeper per frame, and only releases it when a frame with the END_HEADERS flag arrives. The only guard on this accumulator is Mint.HTTP2.assert_header_block_within_max_size/2, which sums the byte size of the fragments received so far. Because a CONTINUATION frame is permitted by the protocol to carry a zero-length payload, an unbounded chain of zero-length CONTINUATION frames adds no bytes to the running total, never trips the size cap, and never emits END_HEADERS, yet each frame still nests the accumulator one level deeper.
A malicious HTTP/2 server (reachable directly, via an attacker-controlled redirect, via SSRF, or via a man-in-the-middle) can open a stream by sending a HEADERS frame without END_HEADERS and then stream zero-length CONTINUATION frames indefinitely. Client memory grows one cons cell per frame received; sustained bandwidth from the peer drives the BEAM node running the Mint client to memory exhaustion and eventual out-of-memory termination.
This issue affects mint: from 0.1.0 before 1.9.2.
Affected Packages
https://github.com/elixir-mint/mint.git (GITHUB):
Affected version(s) >=v0.1.0 <v1.9.2Fix Suggestion:
Update to version v1.9.2mint (HEX):
Affected version(s) >=0.1.0 <1.9.2Fix Suggestion:
Update to version 1.9.2Related Resources (10)
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Contact UsCVSS v4
Base Score:
6.3
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
PRESENT
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
LOW
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
5.3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Weakness Type (CWE)
Allocation of Resources Without Limits or Throttling
EPSS
Base Score:
0.30