Vulnerability in Bouncycastle Fips Java API
CVE-2020-26939
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.009 (60.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 60th percentile — 60.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/bcgit/bc-java/wiki/CVE-2020-26939 (Patch, Third Party Advisory)
- lists.apache.org/thread.html/r8c36ba34e80e05eecb1f80071cc834d705616f315b634ec0c… (mailing-list)
Frequently asked questions
- What is CVE-2020-26939?
- CVE-2020-26939 is a medium-severity vulnerability in Bouncycastle Fips Java API, classified under Observable Discrepancy. CVSS score: 5.3/10. Published 2020-11-02.
- How severe is CVE-2020-26939?
- Medium severity. CVSS v3 base score is 5.3 out of 10.
- Is CVE-2020-26939 known to be exploited?
- 9 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.