CVE-2024-51502Public exploitNetwork attack vector

Decoder panic via truncated HPACK size update

Published Nov 4, 2024 · Updated Nov 21, 2024

Improper exception handling in Bearcove Loona before 0.4.3 allows remote authenticated users to trigger a panic via malformed HPACK input. The loona-hpack Decoder's update_max_dynamic_size function unwraps a failed decode_integer result after a truncated SizeUpdate field instead of returning an error. An application must decode attacker-controlled HPACK data; an uncaught panic terminates the consuming process.

CVSS severity5.1
Medium
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper exception handling in Bearcove Loona before 0.4.3 allows remote authenticated users to trigger a panic via malformed HPACK input. The loona-hpack Decoder's update_max_dynamic_size function unwraps a failed decode_integer result after a truncated SizeUpdate field instead of returning an error. An application must decode attacker-controlled HPACK data; an uncaught panic terminates the consuming process.

The record

CVE
CVE-2024-51502
Published
Nov 4, 2024
Updated
Nov 21, 2024
Vendor
Bearcove
Product
Loona
Classifications
CWE-755, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Nov 4, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 21, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=< 0.4.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Bearcove · Loonaversion=< 0.4.3

Published CVSS scores

5.1GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:L/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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-755Improper Handling of Exceptional Conditions
T1499Endpoint Denial of Service

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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