Security readout for executives and security teams
Plain-English summary
Thunderbird could run script-bearing links embedded in certain HTML object or embed elements. A victim must interact, but successful exploitation could expose sensitive information or alter data. Mozilla released corrected Firefox and Thunderbird versions.
Executive priority
Treat this as a high-priority update because compromise could materially affect data confidentiality and integrity. Accelerate patching on email-facing endpoints, while recognizing that active exploitation is not established by the supplied evidence.
Technical view
This CWE-80 flaw allowed javascript: URLs to execute from object and embed tags in Thunderbird. CVSS 3.1 rates it 8.1: network-reachable, low complexity, no privileges, user interaction required, with high confidentiality and integrity impact but no availability impact.
Likely exposure
Organizations may be exposed where unsupported or older Thunderbird builds process attacker-controlled HTML. Firefox also appears in the fixed-version list, although the bundle describes the vulnerable execution behavior specifically in Thunderbird. Inventory both products and verify release channels.
Exploitation context
The supplied record is not in CISA KEV and provides no evidence of active exploitation. Exploitation requires user interaction. Treat malicious email or other attacker-controlled HTML as the likely delivery context, but the sources do not document observed campaigns.
Researcher notes
The bundle labels corrected versions within an affected-products field, creating ambiguity. The explicit description states those releases contain the fix, so they should be treated as remediation baselines. Bug-level exploitability details and the precise Firefox attack path are not established here.
Mitigation direction
- Update Firefox to 141, ESR 128.13, ESR 140.1, or a later supported release.
- Update Thunderbird to 141, ESR 128.13, ESR 140.1, or a later supported release.
- Prioritize systems processing untrusted email or web content.
- Review Mozilla guidance for channel-specific deployment requirements.
Validation and detection
- Inventory installed Firefox and Thunderbird versions across managed endpoints.
- Confirm each installation meets or exceeds its listed corrected release.
- Verify updates completed successfully through endpoint-management reporting.
- Review security telemetry for suspicious HTML messages containing object or embed elements.
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-80: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2025-8029 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
- High
- CVSS
- 8.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
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:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N2.85.2CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
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://bugzilla.mozilla.org/show_bug.cgi?id=1928021CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2025-56/CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2025-58/CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2025-59/CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2025-61/CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2025-62/CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2025-63/CVE reference, mozilla
- https://lists.debian.org/debian-lts-announce/2025/07/msg00016.htmlCVE reference, CVE
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.
Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.