CVE-2026-53900

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.10% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 0.8% of scored records. A rank, not a probability.

NVD base score

4.3 (CVSS v3.x), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

NVD analysis status

Analyzed. NVD last modified this record on 2026-10-26.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-06-16 11:53Z4 MO AGO

Last updated

2026-06-16 14:37Z4 MO AGO

Reserved

2026-06-11

Assigning CNA

mozilla

Record state

PUBLISHED

Severity

Medium (CVSS 4.3)

CNA CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

Weaknesses

• CWE-345Insufficient Verification of Data AuthenticityClass
• CWE-384Session FixationCompound

Data version

5.2

Document digest

fbe4fa5fade528b1bdc5ccf5710f6aa88253bdd00071211e97bcd4bc0e312706

• bugzilla.mozilla.orghttps://bugzilla.mozilla.org/show_bug.cgi?id=2043204
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-56/