CVE-2026-0890: mozilla firefox Authentication Bypass by Spoofing
CVSS: 5.4v3.1MediumModified
AliasesUBUNTU-CVE-2026-0890DEBIAN-CVE-2026-0890CGA-36c2-f54c-m7fjCGA-f9v8-q55q-23vgCGA-vf2p-fcj5-jcrvCGA-vfgf-m2f7-27rp
Published 13-01-2026Last modified 13-04-2026
Vulnerability summary
CVE-2026-0890 is a medium (CVSS 5.4) Authentication Bypass by Spoofing vulnerability in mozilla firefox. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 21.4% of scored vulnerabilities.
CVSS score
5.4/10
010
Medium · v3.1 (CVE.org)EPSS score
0.30%
0%100%
Low · -0.01 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 38 · Related 11DLA-4439-1DLA-4442-1DSA-6101-1DSA-6103-1MGASA-2026-0013MGASA-2026-0014OPENSUSE-SU-2026:10037-1OPENSUSE-SU-2026:10046-1OPENSUSE-SU-2026:10058-1OPENSUSE-SU-2026:20041-1OPENSUSE-SU-2026:20391-1RHSA-2026:0667RHSA-2026:0694RHSA-2026:0924RHSA-2026:1320RHSA-2026:1413RHSA-2026:1414RHSA-2026:1415RHSA-2026:1461RHSA-2026:1462RHSA-2026:1471RHSA-2026:1487RHSA-2026:2041RHSA-2026:2043RHSA-2026:2044RHSA-2026:2047RHSA-2026:2069RHSA-2026:2070RHSA-2026:2073RHSA-2026:2074RHSA-2026:2220RHSA-2026:2231RHSA-2026:2271RHSA-2026:2286SUSE-SU-2026:0122-1SUSE-SU-2026:0153-1SUSE-SU-2026:0260-1SUSE-SU-2026:20086-1CGA-9HP7-648F-RX6RUSN-7991-1
Timeline
- 13-01-2026PublishedVulnerability first disclosed.
- 13-04-2026Last modifiedVulnerability information updated.
Description
Spoofing issue in the DOM: Copy & Paste and Drag & Drop component. This vulnerability was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
CVSS metrics
6 scores · 6 sources · 1 versionMedium 5.4Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:LSourcesAll 6 agree
- OSV · UbuntuEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
- OSV · DebianEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
- OSV · WolfiEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
- OSV · ChainguardEcosystem advisory · calculated5.4MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
- NVDNIST5.4MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:L
EPSS trend
Probability
0.30%
Chance of exploitation in the next 30 days
Percentile
21%
Versus all other CVEs
30-day change
-0.01 pp
From 0.30% on 21-09-2026
21-09-202621-10-2026
EPSS score0.30%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu8 products
- mozjs102All versions (No fix recorded)
- mozjs115All versions (No fix recorded)
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
- mozjs68All versions (No fix recorded)
Chainguard2 products
- firefox< 140.7-r0
- firefox-esr< 140.7-r0
Debian2 products
- firefox-esr< 140.7.0esr-1~deb12u1 | < 140.7.0esr-1~deb13u1 | < 140.7.0esr-1
- thunderbird< 1:140.7.0esr-1~deb12u1 | < 1:140.7.0esr-1~deb13u1 | < 1:140.7.0esr-1
Mozilla2 products
- firefox< 140.7.0 | < 147.0
- thunderbird< 140.7.0 | < 147.0
Wolfi1 product
- firefox< 140.7-r0
5 vendors · 15 products
