CVE-2026-58229
Unbounded HTTP/1 response-header and chunked-trailer accumulation in Mint causes memory-exhaustion DoS
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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-58229 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-58229 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-58229. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-58229 in your dependencies?
O3 detects CVE-2026-58229 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.