Vulnerability · CVE-2026-103601
Release of unverified plaintext in the CCM (CcmBlockCipher) and DSTU 7624 CCM (KCcmBlockCipher) AEAD modes in Legion of the Bouncy Castle Inc.
Published Oct 2, 2026 · catalog updated Oct 28, 2026 · Release of unverified plaintext
Last checked Oct 28, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-103601. EPSS is 0.33%. Act only if a listed version of Release of unverified plaintext is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (Release of unverified plaintext).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
- CVE-2026-63578 · High
- CVE-2026-63577 · High
- CVE-2026-63576 · High
- CVE-2026-63575 · High
- CVE-2026-63574 · High
- Severity
- High8.2
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.33%
- Remediation
- Version ranges on file
- Affected products
- cpe bouncycastle/bc-csharp
Release of unverified plaintext in the CCM (CcmBlockCipher) and DSTU 7624 CCM (KCcmBlockCipher) AEAD modes in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker to obtain decryptions of ciphertexts of their choosing via forged messages sent to an application that lets the output buffer of a failed decryption be observed, for example through buffer reuse or logging, because decryption wrote the recovered plaintext into the caller-supplied output buffer before checking the authentication tag and left it there when the check failed. Only decryption into a caller-supplied buffer is affected; methods that return a newly allocated array are not.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe bouncycastle/bc-csharp< 2.7.0
How to fix CVE-2026-103601
Upgrade
CVE-2026-103601 lists a fix boundary at 2.7.0. Compare the installed build with that boundary before you change production.
Version check
Affected < 2.7.0
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-103601. EPSS is 0.33%. Act only if a listed version of Release of unverified plaintext is installed.
Which versions are affected?
Compare what you have installed with < 2.7.0. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-354. EPSS 0.33%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 2, 2026 · NIST NVD
Detected
Release of unverified plaintext in the CCM (CcmBlockCipher) and DSTU 7624 CCM (KCcmBlockCipher) AEAD modes in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker to obtain decryptions of ciphertexts of their choosing via forged messages sent to an application that lets the output buffer of a failed decryption be observed, for example through buffer reuse or logging, be
Oct 28, 2026 · NIST NVD
Updated
Release of unverified plaintext in the CCM (CcmBlockCipher) and DSTU 7624 CCM (KCcmBlockCipher) AEAD modes in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker to obtain decryptions of ciphertexts of their choosing via forged messages sent to an application that lets the output buffer of a failed decryption be observed, for example through buffer reuse or logging, be
Sources
- CVE.orgVulnerability recordCVE-2026-103601
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-103601
Release of unverified plaintext in the CCM (CcmBlockCipher) and DSTU 7624 CCM (KCcmBlockCipher) AEAD modes in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker to obtain decryptions of ciphertexts of their choosing via forged messages sent to an app
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 28, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- CVE.orgOct 28, 2026
- NIST NVDOct 28, 2026