CVE-2026-59648Network attack vector

Denial of service via attacker-controlled Argon2 parameters

Published Aug 3, 2026 · Updated Aug 3, 2026

Resource exhaustion in Bouncy Castle Java OpenPGP before 1.85 allows remote attackers to cause an out-of-memory failure or long hang. S2K.Argon2Params accepts packet-controlled pass, parallelism, and memory-exponent bytes, and PGPUtil.makeKeyFromPassPhrase forwards them to Argon2BytesGenerator with a memory ceiling near 1 TiB. Triggering requires a user to enter a passphrase for a crafted SKESK or secret-key packet; Java LTS before 2.73.12 and FIPS bcpg-fips before 1.0.13, 2.0.13, or 2.1.13 are also affected.

CVSS severity6.9
Medium
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Bouncy Castle Java OpenPGP before 1.85 allows remote attackers to cause an out-of-memory failure or long hang. S2K.Argon2Params accepts packet-controlled pass, parallelism, and memory-exponent bytes, and PGPUtil.makeKeyFromPassPhrase forwards them to Argon2BytesGenerator with a memory ceiling near 1 TiB. Triggering requires a user to enter a passphrase for a crafted SKESK or secret-key packet; Java LTS before 2.73.12 and FIPS bcpg-fips before 1.0.13, 2.0.13, or 2.1.13 are also affected.

The record

CVE
CVE-2026-59648
Published
Aug 3, 2026
Updated
Aug 3, 2026
Vendor
Legion of the Bouncy Castle Inc.
Product
Bouncy Castle Java
Classifications
CWE-770, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2026Record 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=1.71 <1.85

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Legion of the Bouncy Castle Inc. · Bouncy Castle Javaversion=1.71 <1.85
Legion of the Bouncy Castle Inc. · Bouncy Castle FIPS Java APIversion=1.0.6 <1.0.13; version=2.0.0 <2.0.13; version=2.1.0 <2.1.13
Legion of the Bouncy Castle Inc. · Bouncy Castle Java LTSversion=2.73.0 <2.73.12

Published CVSS scores

6.9bcorgCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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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