CVE-2026-58229

Unbounded HTTP/1 response-header and chunked-trailer accumulation in Mint causes memory-exhaustion DoS

Published Jul 14, 2026 CVSS 4.0 · 8.2 High EPSS < 1% KEV · Not listed
Description
Allocation of resources without limits vulnerability in elixir-mint mint allows a remote HTTP server to exhaust memory on the client host and cause a denial of service.

The Mint.HTTP1.decode_headers/5 and Mint.HTTP1.decode_trailer_headers/4 functions in lib/mint/http1.ex accumulate every parsed response header and chunked-trailer field into a per-request list that persists across incoming TCP segments as request.headers_buffer, and only clear it when the terminating blank line is received. The section has no cap on the number of headers or on total bytes, and the underlying :erlang.decode_packet(:httph_bin, binary, []) parser is invoked with an empty option list so its per-line and per-packet size limits also default to unlimited.

A malicious HTTP server (reachable directly, via an attacker-controlled redirect, via SSRF, or via a man-in-the-middle) can stream complete header lines (or, after a chunked body, complete trailer lines) indefinitely without ever emitting the terminating blank line. The connection state grows without bound until the BEAM node is killed by the operating system's out-of-memory handler, taking down the entire application that uses Mint as an HTTP client.

This issue affects mint: from 0.1.0 before 1.9.2.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Allocation of resources without limits vulnerability in elixir-mint mint allows a remote HTTP server to exhaust memory on the client host and cause a denial of service. The Mint.HTTP1.decode_headers/5 and Mint.HTTP1.decode_trailer_headers/4 functions in lib/mint/http1.ex accumulate every parsed response header and chunked-trailer field into a per-request list that persists across incoming TCP segments as request.headers_buffer, and only clear it when the terminating blank line is received. The section has no cap on the number of headers or on total bytes, and the underlying :erlang.decode_packet(:httph_bin, binary, []) parser is invoked with an empty option list so its per-line and per-packet size limits also default to unlimited. A malicious HTTP server (reachable directly, via an attacker-controlled redirect, via SSRF, or via a man-in-the-middle) can stream complete header lines (or, after a chunked body, complete trailer lines) indefinitely without ever emitting the terminating blank line. The connection state grows without bound until the BEAM node is killed by the operating system's out-of-memory handler, taking down the entire application that uses Mint as an HTTP client. This issue affects mint: from 0.1.0 before 1.9.2.
Title Unbounded HTTP/1 response-header and chunked-trailer accumulation in Mint causes memory-exhaustion DoS
First Time appeared Elixir-mint
Elixir-mint mint
Weaknesses CWE-770
CPEs cpe:2.3:a:elixir-mint:mint:*:*:*:*:*:*:*:*
Vendors & Products Elixir-mint
Elixir-mint mint
References
Metrics cvssV4_0

{'score': 8.2, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
EEF
Published
Updated
Jul 14, 2026, 3:07 PM
Reserved
Jun 29, 2026, 6:54 PM
Status
Deferred
Published
Jul 14, 2026, 9:16 AM
Modified
Jul 15, 2026, 8:17 PM