CVE-2025-4919: mozilla firefox Out-of-bounds Read
CVSS: 8.8v3.1HighModified
AliasesUBUNTU-CVE-2025-4919DEBIAN-CVE-2025-4919CGA-3m9f-4vq7-6v8cCGA-p9gp-qjmj-9w44CGA-4jpc-7qwr-r5g2CGA-94x4-3v4x-hpc3
Published 17-05-2025Last modified 13-04-2026
Vulnerability summary
CVE-2025-4919 is a high (CVSS 8.8) Out-of-bounds Read vulnerability in mozilla firefox. EPSS estimates a 8.67% chance of exploitation in the next 30 days, higher than 95% of scored vulnerabilities.
CVSS score
8.8/10
010
High · v3.1 (CVE.org)EPSS score
8.67%
0%100%
Low · +0.05 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 34 · Duplicates 1 · Related 8DLA-4172-1DLA-4194-1DSA-5922-1DSA-5932-1MGASA-2025-0165MGASA-2025-0168OPENSUSE-SU-2025:15133-1OPENSUSE-SU-2025:15148-1OPENSUSE-SU-2025:15149-1RHSA-2025:8049RHSA-2025:8060RHSA-2025:8125RHSA-2025:8369RHSA-2025:8370RHSA-2025:8371RHSA-2025:8465RHSA-2025:8598RHSA-2025:8599RHSA-2025:8607RHSA-2025:8608RHSA-2025:8628RHSA-2025:8629RHSA-2025:8630RHSA-2025:8631RHSA-2025:8639RHSA-2025:8640RHSA-2025:8642RHSA-2025:8645RHSA-2025:8756RHSA-2025:8807SUSE-SU-2025:01701-1SUSE-SU-2025:01710-1SUSE-SU-2025:01813-1USN-7663-1CVE-2025-4921CGA-CVPM-FW2W-JGHQ
Timeline
- 17-05-2025PublishedVulnerability first disclosed.
- 13-04-2026Last modifiedVulnerability information updated.
Description
An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes. This vulnerability was fixed in Firefox 138.0.4, Firefox ESR 128.10.1, Firefox ESR 115.23.1, Thunderbird 128.10.2, and Thunderbird 138.0.2.
CVSS metrics
6 scores · 6 sources · 1 versionHigh 8.8Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HSourcesAll 6 agree
- OSV · UbuntuEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · WolfiEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- OSV · ChainguardEcosystem advisory · calculated8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- NVDNIST8.8HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS trend
Probability
8.67%
Chance of exploitation in the next 30 days
Percentile
95%
Versus all other CVEs
30-day change
+0.05 pp
From 8.63% on 19-09-2026
19-09-202619-10-2026
EPSS score8.67%
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< 128.10.1-r0
- firefox-esr< 115.23.1-r0
Debian2 products
- firefox-esr< 128.10.1esr-1~deb12u1 | < 128.10.1esr-1
- thunderbird< 1:128.11.0esr-1~deb12u1 | < 1:128.11.0esr-1
Mozilla2 products
- firefox< 115.23.1 | < 138.0.4 | ≥ 116.0, < 128.10.1
- thunderbird< 128.10.2 | ≥ 138.0, < 138.0.2
Wolfi1 product
- firefox< 128.10.1-r0
5 vendors · 15 products
