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CVE-2020-26939

Published: Nov 2, 2020Updated: Jul 17, 2025 Sources: CVE List NVD GHSACWE-203
NVD MITRE
5.3CVSSMEDIUM
EPSS Score
0.9%
Top 44.9%
CISA KEV
Not in KEV
Exploits
1 Known
Remediation
Patch Available

Description

In Legion of the Bouncy Castle BC before 1.61 and BC-FJA before 1.0.1.2, attackers can obtain sensitive information about a private exponent because of Observable Differences in Behavior to Error Inputs. This occurs in org.bouncycastle.crypto.encodings.OAEPEncoding. Sending invalid ciphertext that decrypts to a short payload in the OAEP Decoder could result in the throwing of an early exception, potentially leaking some information about the private exponent of the RSA private key performing the encryption.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:LI:NA:N
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:NIntegrity
None
A:NAvailability
None
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Weaknesses

CWE-203

Affected Products

fips java apibouncycastle
Library
OSS Libraries / generic-library
legion-of-the-bouncy-castlebouncycastle
Library
OSS Libraries / generic-library
n/an/a
org.bouncycastle:bcprov-jdk14MavenOSS Libraries
org.bouncycastle:bcprov-jdk15MavenOSS Libraries
bouncycastleoss-projectOSS Librariesaka bouncycastle
mavenpackage-ecosystemOSS Libraries
and 6 more affected products View all →

Attack Graph

Products CVE Techniques Tactics

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Exploitability

1 exploit source identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available

MITRE ATT&CK

1 technique
Discovery
View detailed technique mapping

References

https://github.com/bcgit/bc-java/wiki/CVE-2020-26939
github.com
https://lists.apache.org/thread.html/r8c36ba34e80e05eecb1f80071cc834d705616f315b634ec0c7d8f42e%40%3Cissues.solr.apache.org%3E
lists.apache.org
https://nvd.nist.gov/vuln/detail/CVE-2020-26939
nvd.nist.gov
and 4 more references View all →

Timeline

Published
Nov 2, 2020
Last Updated
Jul 17, 2025

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