CVE-2026-56810
Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint mint (Mint.HTTP1 module) allows a denial of service via an oversized chunked transfer-encoded response. This…
Description
Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint mint (Mint.HTTP1 module) allows a denial of service via an oversized chunked transfer-encoded response.
This vulnerability is associated with program files lib/mint/http1.ex and program routines 'Elixir.Mint.HTTP1':decode_body/5, 'Elixir.Mint.HTTP1':add_body_to_buffer/2.
When Mint decodes a chunked HTTP response body, it accumulates each partial fragment of the current chunk in the connection's data_buffer (an unbounded iolist) via add_body_to_buffer/2 and does not emit the data to the caller until the full declared chunk length has been received. The chunk size is taken directly from the server and parsed with no upper bound, so a malicious or compromised server can announce one enormous chunk (for example a size line of 7FFFFFFF, about 2 GiB) and then send the body bytes slowly without ever completing the chunk. The client buffers every received byte while it waits for a completion that never arrives, and because no data responses are produced until the chunk finishes, a caller that otherwise streams large content-length bodies safely gains no protection. An unauthenticated remote server (reachable whenever a client follows redirects, fetches user-supplied URLs, or processes webhooks) can drive the client's memory arbitrarily high and trigger an out-of-memory condition.
This issue affects mint: from 0.5.0 before 1.9.1.
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-2026-56810 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-2026-56810 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-2026-56810. 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-2026-56810 in your dependencies?
O3 detects CVE-2026-56810 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.