CVE-2020-26939
mediumpriority · track · 21EPSS 0.009 · 60 %ileEUFRUSEPSS · scored 2026-10-27
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (11)
Products and version ranges known to be affected.
- bouncycastle legion-of-the-bouncy-castle< 1.61nvdUScpe:2.3:a:bouncycastle:legion-of-the-bouncy-castle:*:*:*:*:*:*:*:*
advisories (2)
Vendor and ecosystem advisories describing this.
- GHSA-72m5-fvvv-55m6Observable Differences in Behavior to Error Inputs in Bouncy Castle2021-04-22ghsa · osvUS
In Legion of the Bouncy Castle BC before 1.55 and BC-FJA before 1.0.2, 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.
- CERTFR-2026-AVI-1336Multiples vulnérabilités dans les produits IBMFrançais2026-10-16vendor · certfrFR
also known as (3)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (19)
External citations — patches, advisories, analysis.
- https://github.com/bcgit/bc-java/commit/930f8b274c4f1f3a46e68b5441f1e7fadb57e8c1cnnvd
- https://github.com/bcgit/bc-java/wiki/CVE-2020-26939cnnvd
- https://lists.apache.org/thread.html/r8c36ba34e80e05eecb1f80071cc834d705616f315b634ec0c7d8f42e%40%3Cissues.solr.apache.org%3Ecnnvd
- https://lists.apache.org/thread.html/r8c36ba34e80e05eecb1f80071cc834d705616f315b634ec0c7d8f42e@%3Cissues.solr.apache.org%3Ecnnvd
- https://lists.debian.org/debian-lts-announce/2020/11/msg00007.htmlcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2020-26939cnnvd
- https://security.netapp.com/advisory/ntap-20201202-0005/cnnvd
- https://vigilance.fr/vulnerability/Bouncy-Castle-information-disclosure-via-OAEPEncoding-Observable-Differences-33769cnnvd
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