Security readout for executives and security teams
Plain-English summary
This issue can make affected Bouncy Castle Java crypto libraries fail AES-GCM decryption with a bad authentication tag exception. The known impact is limited availability loss, not data theft or data modification. Exposure is specific to certain Linux x86_64 builds using AVX or AVX-512f optimized code paths.
Executive priority
Treat this as a targeted availability risk for systems relying on affected Bouncy Castle GCM decryption. It does not indicate confidentiality or integrity compromise in the supplied record, but failed decryption can disrupt services and should be remediated in normal patch cycles.
Technical view
CVE-2026-8149 affects BC-LTS bcprov-lts8on 2.73.0 through before 2.73.11 and BC-FJA bc-fips 2.1.0 through before 2.1.3 on Linux x86_64 with AVX or AVX-512f. The issue is associated with GCM chunking code in gcm128w and gcm512w files and can cause bad tag exceptions during decryption.
Likely exposure
Organizations are likely exposed only where affected Bouncy Castle package versions run on Linux x86_64 systems using AVX or AVX-512f. Java applications that depend on these libraries for GCM decryption are the main concern.
Exploitation context
The CVE is not listed as KEV, and the supplied sources do not report active exploitation. CVSS 4.0 rates it 5.1 with local attack vector, low complexity, no privileges, no user interaction, and low availability impact only.
Researcher notes
The public bundle gives product ranges, platform constraints, CVSS, and associated source files, but does not include root-cause detail, exploit prerequisites beyond CVSS, or workaround instructions. Validation should focus on dependency versioning, platform matching, and observed decryption failure patterns.
Mitigation direction
- Upgrade BC-LTS bcprov-lts8on to 2.73.11 or later.
- Upgrade BC-FJA bc-fips to 2.1.3 or later.
- Check the vendor advisory for supported upgrade guidance.
- Prioritize systems where affected libraries handle production decryption paths.
- Monitor application logs for recurring GCM bad tag exceptions.
Validation and detection
- Inventory Java dependencies for bcprov-lts8on and bc-fips packages.
- Confirm exact deployed versions against the affected ranges.
- Check whether affected deployments run on Linux x86_64 with AVX or AVX-512f.
- Review application logs for decryption failures matching bad tag exceptions.
- Verify upgraded environments no longer use vulnerable package versions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-1068: Exact CWE lookup
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Open ATT&CK lookupCVE-2026-8149 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 5.1 (4.0)
- Known Exploited
- No
- Published
Vector: 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/S:N/RE:M/U:Amber
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
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/S:N/RE:M/U:Amber——bcorgVulnerability scoring details
Base CVSS 4.0 score
5.1MediumVector: 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/S:N/RE:M/U:Amber
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%908149CVE reference, bcorg · vendor-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Inconsistency Between Implementation and Documented Design
Inconsistency Between Implementation and Documented Design represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.