GCM chunking can lead to bad tag exception on decryption

MITRE NVD CVE.ORG JSON API Print: PDF PDF

Summary

CVECVE-2026-8149
StatePUBLISHED
Assignerbcorg
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-05-08 07:16:29 UTC
Updated2026-05-08 07:16:29 UTC
DescriptionA vulnerability in Legion of the Bouncy Castle Inc. BC-FJA BC-FIPS on Linux, X86_64, AVX, AVX-512f. This vulnerability is associated with program files gcm128w, gcm512w. This issue affects BC-FJA: from 2.1.0 through 2.1.2.

Risk And Classification

Primary CVSS: v4.0 5.1 MEDIUM from 91579145-5d7b-4cc5-b925-a0262ff19630

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:X/R:X/V:X/RE:M/U:Amber

Problem Types: CWE-1068 | CWE-1068 CWE-1068

VersionSourceTypeScoreSeverityVector
4.091579145-5d7b-4cc5-b925-a0262ff19630Secondary5.1MEDIUMCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/C...
4.0CNACVSS5.1MEDIUMCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/S:N/R...

CVSS v4.0 Breakdown

Attack Vector
Local
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:X/R:X/V:X/RE:M/U:Amber

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Legion Of The Bouncy Castle Inc. BC-FJA affected 2.1.0 2.1.2 maven Linux, X86_64, AVX, AVX-512f

References

ReferenceSourceLinkTags
do-not-publish.bouncycastle.org/do_not_publish 91579145-5d7b-4cc5-b925-a0262ff19630 do-not-publish.bouncycastle.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Michael Schäfer, Kiteworks (en)

Additional Advisory Data

Workarounds

CNA: If possible pass whole message to GCM via doFinal(..) for decryption. Issue only occurs when decryption is chunked at certain boundaries.

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