CVE-2026-58226Public exploitNetwork attack vector

Unauthenticated denial of service via unbounded HPACK integers

Published Jul 6, 2026 · Updated Jul 6, 2026

Inefficient integer decoding in Elixir Mint hpax 0.1.1 through 1.0.3 allows remote attackers to interrupt HTTP/2 services. The decode_remaining_integer/3 routine accepts unlimited continuation octets and repeatedly adds increasingly large arbitrary-precision values. Any unauthenticated peer able to submit an HPACK header block to a consuming HTTP/2 endpoint can impose superlinear CPU work and transient memory use.

CVSS severity8.7
High
EPSS probability0.55%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Inefficient integer decoding in Elixir Mint hpax 0.1.1 through 1.0.3 allows remote attackers to interrupt HTTP/2 services. The decode_remaining_integer/3 routine accepts unlimited continuation octets and repeatedly adds increasingly large arbitrary-precision values. Any unauthenticated peer able to submit an HPACK header block to a consuming HTTP/2 endpoint can impose superlinear CPU work and transient memory use.

The record

CVE
CVE-2026-58226
Published
Jul 6, 2026
Updated
Jul 6, 2026
Vendor
Elixir Mint
Product
hpax
Classifications
CWE-407, CAPEC-130, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.1.1 <1.0.4
  2. Affected versionversion=56db437a7e2c515e3bdd770ac7947b02cd2390d0 <1ba4bb2dc91e80089cf89c73970ac3ded76f17eb

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Elixir Mint · hpaxversion=0.1.1 <1.0.4; version=56db437a7e2c515e3bdd770ac7947b02cd2390d0 <1ba4bb2dc91e80089cf89c73970ac3ded76f17eb

Published CVSS scores

8.7Erlang Ecosystem FoundationCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-407Inefficient Algorithmic Complexity
CAPEC-130Excessive Allocation
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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