CVE-2026-54892Public exploitNetwork attack vector

Unauthenticated service interruption via quadratic parameter decoding

Published Jun 23, 2026 · Updated Jun 23, 2026

Algorithmic complexity in Plug's nested-parameter decoder allows remote attackers to interrupt Plug-based HTTP services with crafted keys. Plug.Conn.Query.split_keys/6 builds growing binary prefixes, while insert_keys/3 and finalize_pointer/2 repeatedly hash and map those prefixes, making decode cost quadratic in bracket depth. No authentication or route knowledge is required; concurrent requests can pin every BEAM scheduler and leave the service unresponsive.

CVSS severity8.7
High
EPSS probability0.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Algorithmic complexity in Plug's nested-parameter decoder allows remote attackers to interrupt Plug-based HTTP services with crafted keys. Plug.Conn.Query.split_keys/6 builds growing binary prefixes, while insert_keys/3 and finalize_pointer/2 repeatedly hash and map those prefixes, making decode cost quadratic in bracket depth. No authentication or route knowledge is required; concurrent requests can pin every BEAM scheduler and leave the service unresponsive.

The record

CVE
CVE-2026-54892
Published
Jun 23, 2026
Updated
Jun 23, 2026
Vendor
elixir-plug
Product
Plug
Classifications
CWE-407, CAPEC-229, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 23, 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=1.15.0 <1.15.5
  2. Affected versionversion=1.16.0 <1.16.4
  3. Affected versionversion=1.17.0 <1.17.2
  4. Affected versionversion=1.18.0 <1.18.3
  5. Affected versionversion=1.19.0 <1.19.3
  6. Affected versionversion=712b875d3442c765d8d37e546ffd5ad9f8afcc55 <* changes=[{"at":"c317d08fdcf96e17931f7419275b2b8c4bf3e951","status":"unaffected"},{"at":"9c5d37c440eaae92869eed7c014c47266744fadb","status":"unaffected"},{"at":"d737eb236f17e31a36290e39f9ef3cd86a1343bd","status":"unaffected"},{"at":"d4e5568392a4b29e545b91e12e87d6098f976145","status":"unaffected"},{"at":"a61124aa625d819a218fb07f90afbac8aa85eb0e","status":"unaffected"}]

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

elixir-plug · Plugversion=1.15.0 <1.15.5; version=1.16.0 <1.16.4; version=1.17.0 <1.17.2; version=1.18.0 <1.18.3; version=1.19.0 <1.19.3; version=712b875d3442c765d8d37e546ffd5ad9f8afcc55 <* changes=[{"at":"c317d08fdcf96e17931f7419275b2b8c4bf3e951","status":"unaffected"},{"at":"9c5d37c440eaae92869eed7c014c47266744fadb","status":"unaffected"},{"at":"d737eb236f17e31a36290e39f9ef3cd86a1343bd","status":"unaffected"},{"at":"d4e5568392a4b29e545b91e12e87d6098f976145","status":"unaffected"},{"at":"a61124aa625d819a218fb07f90afbac8aa85eb0e","status":"unaffected"}]

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-229Serialized Data Parameter Blowup
T1499.004Application 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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