CVE-2025-5269: mozilla firefox Out-of-bounds Write
CVSS: 8.1v3.1HighModified
AliasesUBUNTU-CVE-2025-5269DEBIAN-CVE-2025-5269CGA-cgqw-783p-vxxgCGA-rj2x-5jg5-8w9gCGA-4693-9qq5-2mw6CGA-93cc-3r2g-cr66
Published 27-05-2025Last modified 13-04-2026
Vulnerability summary
CVE-2025-5269 is a high (CVSS 8.1) Out-of-bounds Write vulnerability in mozilla firefox. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 38.7% of scored vulnerabilities.
CVSS score
8.1/10
010
High · v3.1 (CVE.org)EPSS score
0.46%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 37 · Related 11DLA-4191-1DLA-4194-1DSA-5926-1DSA-5932-1MGASA-2025-0195MGASA-2025-0197OPENSUSE-SU-2025-20135-1OPENSUSE-SU-2025:15170-1OPENSUSE-SU-2025:15174-1OPENSUSE-SU-2025:15315-1OPENSUSE-SU-2025:20135-1RHSA-2025:8293RHSA-2025:8308RHSA-2025:8341RHSA-2025:8598RHSA-2025:8599RHSA-2025:8607RHSA-2025:8608RHSA-2025:8628RHSA-2025:8629RHSA-2025:8630RHSA-2025:8631RHSA-2025:8642RHSA-2025:8756RHSA-2025:9071RHSA-2025:9072RHSA-2025:9073RHSA-2025:9074RHSA-2025:9075RHSA-2025:9076RHSA-2025:9077RHSA-2025:9155SUSE-SU-2025:01769-1SUSE-SU-2025:01814-1SUSE-SU-2025:01946-1SUSE-SU-2025:21170-1USN-7663-1CGA-5H68-PG33-4GH7
Timeline
- 27-05-2025PublishedVulnerability first disclosed.
- 13-04-2026Last modifiedVulnerability information updated.
Description
Memory safety bug present in Firefox ESR 128.10, and Thunderbird 128.10. This bug showed evidence of memory corruption and we presume that with enough effort this could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox ESR 128.11 and Thunderbird 128.11.
CVSS metrics
6 scores · 6 sources · 1 versionHigh 8.1Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:HSourcesAll 6 agree
- OSV · UbuntuEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · WolfiEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · ChainguardEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVDNIST8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.46%
Chance of exploitation in the next 30 days
Percentile
39%
Versus all other CVEs
30-day change
0.00 pp
From 0.46% on 19-09-2026
19-09-202619-10-2026
EPSS score0.46%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Chainguard2 products
- firefox< 128.11-r0
- firefox-esr< 128.11-r0
Debian2 products
- firefox-esr< 128.11.0esr-1~deb12u1 | < 128.11.0esr-1
- thunderbird< 1:128.11.0esr-1~deb12u1 | < 1:128.11.0esr-1
Mozilla2 products
- firefox< 128.11.0
- thunderbird< 128.11.0
Ubuntu1 product
- thunderbird< 1:128.12.0+build1-0ubuntu0.22.04.1
Wolfi1 product
- firefox< 128.11-r0
5 vendors · 8 products
