CVE-2026-53900: mozilla firefox_mobile
CVSS: 4.3v3.1MediumAnalyzed
AliasesCGA-87c8-vh5c-g2qxCGA-gwp5-4cm6-g72q
Published 16-06-2026Last modified 16-06-2026
Vulnerability summary
CVE-2026-53900 is a medium (CVSS 4.3) vulnerability in mozilla firefox_mobile. EPSS estimates a 0.14% chance of exploitation in the next 30 days, higher than 3.3% of scored vulnerabilities.
CVSS score
4.3/10
010
Medium · v3.1 (CVE.org)EPSS score
0.14%
0%100%
Low · +0.04 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 0 · Related 1Timeline
- 16-06-2026PublishedVulnerability first disclosed.
- 16-06-2026Last modifiedVulnerability information updated.
Description
Firefox for iOS preserved cookies set on the initial PDF request across cross-origin HTTP redirects in TemporaryDocument, allowing a malicious site to inject arbitrary cookies into requests to an unrelated target domain. This vulnerability was fixed in Firefox for iOS 152.0.
CVSS metrics
4 scores · 4 sources · 1 versionMedium 4.3Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:NSourcesAll 4 agree
- OSV · WolfiEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
- OSV · ChainguardEcosystem advisory · calculated4.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
- NVDNIST4.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.14%
Chance of exploitation in the next 30 days
Percentile
3%
Versus all other CVEs
30-day change
+0.04 pp
From 0.10% on 21-09-2026
21-09-202621-10-2026
EPSS score0.14%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-345Insufficient Verification of Data AuthenticityThe product does not sufficiently verify the origin or authenticity of data, in a way that causes it to accept invalid data.
- CWE-384Session FixationAuthenticating a user, or otherwise establishing a new user session, without invalidating any existing session identifier gives an attacker the opportunity to steal authenticated sessions.
Affected systems
Chainguard1 product
- firefox< 152.0-r0
Mozilla1 product
- firefox_mobile< 152.0
Wolfi1 product
- firefox< 152.0-r0
3 vendors · 3 products
