CVE-2026-12803

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Source
https://cve.org/CVERecord?id=CVE-2026-12803
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-12803.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-12803
Downstream
Published
2026-08-03T02:52:20.460Z
Modified
2026-08-05T03:32:26.101523361Z
Severity
  • 8.7 (High) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/U:Amber CVSS Calculator
Summary
KCCMBlockCipher MAC does not bind nonce when AAD is absent (cross-nonce AEAD forgery)
Details

In Bouncy Castle for Java before 1.85, KCCMBlockCipher MAC does not bind nonce when AAD is absent (cross-nonce AEAD forgery). This issue also affects Bouncy Castle for Java LTS before 2.73.12.

Database specific 
{
    "cwe_ids": [
        "CWE-354"
    ],
    "cna_assigner": "bcorg",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/12xxx/CVE-2026-12803.json",
    "unresolved_ranges": [
        {
            "source": "AFFECTED_FIELD",
            "extracted_events": [
                {
                    "fixed": "1.85"
                }
            ]
        }
    ]
}
References

Affected packages

Git / github.com/bcgit/bc-lts-java

Affected ranges

Type
GIT
Repo
https://github.com/bcgit/bc-lts-java
Events
Introduced
468b5082f3f0971e80bf9edb7029c17b39b9ba0c
Fixed
f101b232c5d3e07ecdd504210a57e43831d6cd65
Database specific 
{
    "source": "AFFECTED_FIELD",
    "extracted_events": [
        {
            "introduced": "2.73.0"
        },
        {
            "fixed": "2.73.12"
        }
    ]
}

Affected versions

Other
r2rv73dot0
r2rv73dot1
r2rv73dot10
r2rv73dot11
r2rv73dot3
r2rv73dot4
r2rv73dot6
r2rv73dot8
r2rv73dot9

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-12803.json"