Privilege escalation in the Nimbus Desktop Client component. This vulnerability was fixed in Firefox 160, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7.
CVE-2026-124951
UNRATEDCVSS · not yet scoredTrending — Patch released this week
Also known asEUVD-2026-120922 (ENISA EUVD) · GHSA-qw39-vxq2-qq75 (GitHub Security Advisories)Source: ENISA EUVD
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EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS v2: —Exploit: None knownExposed services: Not assessed
A fix is available — apply it.
- CVSS
- —
- EchelonGraph score
- Not yet assessedNo source has published severity data for this CVE yet — no CVSS score from NVD or a CNA, no GitHub advisory, and it is not in CISA KEV. This is not a rating of zero; we cannot assess it yet.
- EG Score
- —
- EG Risk
- —
- EPSS PROB
- 0.2%
- EPSS %ILE
- 7th
- KEV
- Not listed
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
- EG Severity
- Not assessed: no CVSS publishedA missing CVSS is not a severity of zero.
- EG Likelihood
- 0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- No SSVC decision: EchelonGraph has not assessed this CVECISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the BOD 26-04 block below.
BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it
Published
November 10, 2026
Last Modified
November 13, 2026
References (5)
- security@mozillahttps://bugzilla.mozilla.org/show_bug.cgi?id=2085124
- security@mozillahttps://www.mozilla.org/security/advisories/mfsa2026-125/
- security@mozillahttps://www.mozilla.org/security/advisories/mfsa2026-127/
- security@mozillahttps://www.mozilla.org/security/advisories/mfsa2026-128/
- security@mozillahttps://www.mozilla.org/security/advisories/mfsa2026-129/
Vendor Advisories for CVE-2026-124951(6)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- RHSA-2026:99572Red Hat Product SecurityHigh
Red Hat Security Advisory: firefox security update
- RHSA-2026:99571Red Hat Product SecurityHigh
Red Hat Security Advisory: firefox security update
- RHSA-2026:99112Red Hat Product SecurityHigh
Red Hat Security Advisory: firefox security update
- RHSA-2026:99110Red Hat Product SecurityHigh
Red Hat Security Advisory: firefox security update
- RHSA-2026:99111Red Hat Product SecurityHigh
Red Hat Security Advisory: firefox security update
- GHSA-qw39-vxq2-qq75GitHub Security Advisoriesunknown
Privilege escalation in the Nimbus Desktop Client component. This vulnerability was fixed in...
Patch Availability(5)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | firefox-0:153.7.0-1.el10_3 | 2026-11-12 | redhat |
| redhat | firefox-0:153.7.0-1.el10_2 | 2026-11-12 | redhat |
| redhat | firefox-0:153.7.0-1.el8_10 | 2026-11-11 | redhat |
| redhat | firefox-0:153.7.0-1.el9_9 | 2026-11-11 | redhat |
| redhat | firefox-0:153.7.0-1.el9_8 | 2026-11-11 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(3 across 3 ecosystems)
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| firefox-esr | 102.11.0esr-1 ... 153.6.0esr-1~deb13u1 (220 versions) |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| firefox-esr | 128.13.0esr-1 ... 153.6.0esr-1~deb13u1 (95 versions) |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| firefox-esr | 128.13.0esr-1 ... 153.6.0esr-1~deb13u1 (95 versions) |
| — |
Data Freshness Timeline
(refreshed 19× in last 7d / 19× in last 30d)
Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.
- 2026-11-13 05:30 UTCVendor advisory
- 2026-11-13 05:30 UTCGHSA enrichmentGHSA-qw39-vxq2-qq75
- 2026-11-13 05:17 UTCEchelonGraph re-scored
- 2026-11-13 05:17 UTCVendor advisory
- 2026-11-13 05:17 UTCGHSA enrichmentGHSA-qw39-vxq2-qq75
- 2026-11-12 16:33 UTCEPSS rescoreEPSS 0.2% · 7th percentile
- 2026-11-11 16:38 UTCEPSS rescoreEPSS 0.2% · 7th percentile
- 2026-11-10 21:33 UTCGHSA enrichmentGHSA-qw39-vxq2-qq75
- 2026-11-10 21:27 UTCNVD update
- 2026-11-10 20:37 UTCGHSA enrichmentGHSA-qw39-vxq2-qq75
- 2026-11-10 20:29 UTCMITRE cvelistV5
- 2026-11-10 19:42 UTCGHSA enrichmentGHSA-qw39-vxq2-qq75
- 2026-11-10 19:27 UTCNVD update
- 2026-11-10 19:13 UTCGHSA enrichmentGHSA-qw39-vxq2-qq75
- 2026-11-10 19:10 UTCMITRE cvelistV5
- 2026-11-10 16:49 UTCGHSA enrichmentGHSA-qw39-vxq2-qq75
- 2026-11-10 15:48 UTCGHSA enrichmentGHSA-qw39-vxq2-qq75
- 2026-11-10 14:27 UTCNVD update
- 2026-11-10 14:00 UTCENISA EUVD ID recordedEUVD-2026-120922 · Source: ENISA EUVD
- 2026-11-10 13:35 UTCEchelonGraph re-scored
- 2026-11-10 13:34 UTCMITRE cvelistV5first tracked
Related CVEs(same vendor)
Frequently asked(4)
What is CVE-2026-124951?
CVE-2026-124951 is a vulnerability whose severity is not yet rated; its CVE record was published on November 10, 2026. Privilege escalation in the Nimbus Desktop Client component. This vulnerability was fixed in Firefox 160, Firefox ESR 153.7, Thunderbird 160, and Thunderbird 153.7.
When was the CVE record for CVE-2026-124951 published?
The CVE record for CVE-2026-124951 was published on November 10, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of November 13, 2026; the record at its source may have been updated since.
Is CVE-2026-124951 actively exploited?
CVE-2026-124951 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (7th percentile of EPSS-scored CVEs).
How do I remediate CVE-2026-124951?
A fix for CVE-2026-124951 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-124951 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-124951
Is Your Infrastructure Affected by CVE-2026-124951?
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