Security readout for executives and security teams
Plain-English summary
CVE-2026-2798 is a high-severity Mozilla DOM memory-safety bug. A malicious webpage or email-rendered content could potentially cause serious browser or mail-client compromise after user interaction. Mozilla states it was fixed in Firefox 148 and Thunderbird 148.
Executive priority
Treat as high priority for endpoint patching. It affects common user-facing software and has high potential impact, but provided sources do not confirm active exploitation.
Technical view
The issue is a use-after-free in Mozilla’s DOM Core & HTML component, mapped to CWE-416. CVSS 3.1 is 8.8 with network attack vector, low complexity, no privileges, required user interaction, and high confidentiality, integrity, and availability impact.
Likely exposure
Organizations using Mozilla Firefox or Thunderbird before applying the 148 fixes are the main concern. Exposure depends on endpoint browser and mail-client versions, including packaged versions from Linux distributions.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. The CVSS vector indicates exploitation would require user interaction, such as opening attacker-controlled web or rendered content.
Researcher notes
Public detail is limited in the supplied sources. Base analysis on Mozilla’s advisory language, CWE-416 classification, CVSS vector, and vendor fix statements; avoid assuming exploitability beyond those records.
Mitigation direction
- Update Firefox to version 148 or later where applicable.
- Update Thunderbird to version 148 or later where applicable.
- Check Mozilla and distribution vendor advisories for backported package fixes.
- Prioritize managed endpoints that browse the web or handle untrusted email content.
Validation and detection
- Inventory Firefox and Thunderbird versions across managed endpoints.
- Confirm installed packages include the CVE-2026-2798 fix or vendor backport.
- Review vulnerability scanner findings against Mozilla and Red Hat advisory status.
- Monitor Mozilla and Red Hat references for updated affected-version or exploit information.
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-416: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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-2026-2798 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
- 8.8 (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:H
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
2 official scoresWe 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:H2.85.9CISA-ADPCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H1.65.9redhat-SADPVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
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.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-02-24T14:03:58.859Z: Reported to Red Hat.
- 2026-02-24T13:33:28.034Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://bugzilla.mozilla.org/show_bug.cgi?id=2014136CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2026-13/CVE reference, mozilla
- https://www.mozilla.org/security/advisories/mfsa2026-16/CVE reference, mozilla
- https://access.redhat.com/security/cve/CVE-2026-2798CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2442315CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2798.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
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.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.