How severe is CVE-2026-49754?

No CVSS score has been assigned to CVE-2026-49754 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-49754?

CVE-2026-49754 affects the following packages: mint (Hex). Ecosystems affected: Hex.

How do I fix CVE-2026-49754?

Update mint to 1.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-49754 is resolved across your whole dependency graph.

How do I detect CVE-2026-49754 in my Hex dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mint, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-49754 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2026-49754 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-49754 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-49754?

CVE-2026-49754 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 42th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-49754?

CVE-2026-49754 is classified as CWE-770 (CWE-770). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-49754 published, and has it been updated?

CVE-2026-49754 was published on June 2, 2026 and was last updated on August 12, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💧 Hex

Not in CISA KEV

CVE-2026-49754 — mint

Fix: elixir-mint/mint@b662d12

CVE-2026-49754 is a CWE-770 vulnerability in mint. A fix is available for mint — see the affected versions and patch details below.

HTTP/2 CONTINUATION flood in Mint client via unbounded header-block accumulation

Also known asEEF-CVE-2026-49754GHSA-2p26-p43x-fhp8

Published

Jun 2, 2026

Updated

Aug 12, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-49754.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs42th percentile — riskier than 42% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

💧mint

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Hex packages — download data is not available via public APIs for these ecosystems.

Description

Summary

Mint's HTTP/2 client accumulates CONTINUATION header-block fragments into a per-connection buffer with no cap on size or frame count. A malicious or compromised HTTP/2 server can drive the client's memory to arbitrary size by streaming an endless chain of CONTINUATION frames after a HEADERS frame that omits END_HEADERS, causing memory exhaustion and BEAM process death. A single connection to an attacker-controlled HTTP/2 endpoint is sufficient.

Details

When Mint's HTTP/2 receive path observes a HEADERS frame without the END_HEADERS flag, 'Elixir.Mint.HTTP2':handle_headers/3 parks the unparsed header-block fragment in conn.headers_being_processed. Every subsequent CONTINUATION frame on that stream is then appended to the accumulator by 'Elixir.Mint.HTTP2':handle_continuation/3.

Nothing in the receive path bounds this accumulator: there is no per-stream size cap, no CONTINUATION frame-count cap, and max_header_list_size is only enforced on outgoing requests (its default is :infinity, and the only enforcement helper inspects server_settings for request encoding, never inbound header blocks). Each CONTINUATION payload can be up to the peer-advertised SETTINGS_MAX_FRAME_SIZE, so the attacker can grow headers_being_processed to arbitrary size at line rate.

PoC

Stand up a raw TCP server that speaks the HTTP/2 handshake.
After the client's request HEADERS arrives, respond with a HEADERS frame on stream 1 with flags = 0 (no END_HEADERS, no END_STREAM) and an empty header-block fragment.
Stream CONTINUATION frames on stream 1, each with flags = 0 and a payload up to SETTINGS_MAX_FRAME_SIZE. Never set END_HEADERS.
The client's process memory grows linearly with the flood and the BEAM process eventually crashes with OOM.

Impact

Remote, unauthenticated denial-of-service against any process using Mint as an HTTP/2 client against an untrusted or attacker-influenced server. A single connection is sufficient to drive memory to arbitrary size and crash the BEAM process. The default Mint configuration is vulnerable; no client-side opt-in is required. Scored CVSS v4.0 8.2 (HIGH).

Workarounds

Restrict Mint to HTTP/1 on connections to untrusted servers by passing protocols: [:http1] to 'Elixir.Mint.HTTP':connect/4. This avoids the vulnerable HTTP/2 receive path entirely, at the cost of losing HTTP/2 for those connections.

Resources

Introduction commit: https://github.com/elixir-mint/mint/commit/596ca4304504be68939c4929e0831557097962b8
Patch commit: https://github.com/elixir-mint/mint/commit/b662d127d3028b5426c88d4c9cc7fe430491a10b

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💧Hex	`mint`	all versions	1.9.0`mix deps.update mint`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for mint, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update mint to 1.9.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-49754 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

### Summary Mint's HTTP/2 client accumulates `CONTINUATION` header-block fragments into a per-connection buffer with no cap on size or frame count. A malicious or compromised HTTP/2 server can drive the client's memory to arbitrary size by streaming an endless chain of `CONTINUATION` frames after a `HEADERS` frame that omits `END_HEADERS`, causing memory exhaustion and BEAM process death. A single connection to an attacker-controlled HTTP/2 endpoint is sufficient. ### Details When Mint's HTTP/2 receive path observes a `HEADERS` frame without the `END_HEADERS` flag, `'Elixir.Mint.HTTP2':hand

O3 Security · Impact-Aware SCA

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