Security readout for executives and security teams
Plain-English summary
CVE-2026-2797 is a high-severity Mozilla memory-safety flaw in the JavaScript garbage collector. A user likely must open attacker-controlled content, but no login is needed. Mozilla states it was fixed in Firefox 148 and Thunderbird 148.
Executive priority
Treat this as a priority browser and mail-client patching issue. It is high impact, commonly exposed through user activity, and fixed by vendor updates, but the provided sources do not support emergency active-exploitation claims.
Technical view
The issue is a CWE-416 use-after-free in JavaScript: GC. CVSS 3.1 is 8.8 with network attack vector, low complexity, no privileges, user interaction required, and high confidentiality, integrity, and availability impact. The bundle does not provide exploit mechanics.
Likely exposure
Exposure is most likely on systems running Mozilla Firefox or Thunderbird without the 148 security fixes. The supplied affected-version wording is ambiguous because it lists 148 while also saying 148 fixed the issue, so validate against Mozilla and OS vendor package data.
Exploitation context
The source bundle does not show active exploitation, and KEV is false. The CVSS vector indicates exploitation would require user interaction, such as processing attacker-controlled web or message content, but the provided sources do not document a public exploit.
Researcher notes
Focus validation on exact Mozilla build and downstream package status. The bundle identifies the component and CVSS characteristics but does not disclose root-cause detail, proof-of-concept status, exploitability constraints beyond user interaction, or affected pre-fix version ranges.
Mitigation direction
- Update Firefox to version 148 or a vendor-fixed equivalent.
- Update Thunderbird to version 148 or a vendor-fixed equivalent.
- For Linux distributions, apply vendor security updates or confirmed backports.
- Check Mozilla and Red Hat guidance for any product-specific remediation details.
- Prioritize managed endpoints where browsers or mail clients process untrusted content.
Validation and detection
- Inventory Firefox and Thunderbird versions across endpoints and servers.
- Confirm installed builds include the Firefox 148 or Thunderbird 148 fixes.
- For Red Hat systems, compare package status with the Red Hat CVE and CSAF VEX records.
- Review browser and mail client patch compliance reports for unmanaged devices.
- Monitor Mozilla advisories for corrected affected-version details or follow-up fixes.
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-2026-2797 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
- 2026-02-24T14:04:53.278Z: Reported to Red Hat.
- 2026-02-24T13:33:27.406Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://bugzilla.mozilla.org/show_bug.cgi?id=2013561CVE 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-2026-2797CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2442330CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-2797.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.