CVE-2026-8974

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 ImpacttotalSuccessful exploitation gives total 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

0.33% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 26.0% of scored records. A rank, not a probability.

NVD base score

8.8 (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:H/I:H/A:H

NVD analysis status

Modified. NVD last modified this record on 2026-07-23.

Red Hat severity

Moderate. Red Hat's rating for its own products, not a CVSS rating.

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

2026-05-19 12:30Z3 MO AGO

Last updated

2026-05-26 17:47Z3 MO AGO

Reserved

2026-05-19

Assigning CNA

mozilla

Record state

PUBLISHED

Severity

High (CVSS 8.8)

CNA CVSS vector

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

Weaknesses

• CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferClass
• CWE-787Out-of-bounds WriteBase

Data version

5.2

Document digest

f69191e245063d0ecbb18acdb5f7deb800dd8094f612f259dc7a8f92de3991f8

• bugzilla.mozilla.orgMemory safety bugs fixed in Firefox ESR 140.11 and Firefox 151https://bugzilla.mozilla.org/buglist.cgi?bug_id=1784128%2C1883230%2C1983677%2C2022390%2C2023116%2C2023657%2C2024255%2C2024418%2C2024441%2C2024447%2C2024966%2C2025412%2C2025467%2C2025940%2C2025950%2C2025956%2C2026284%2C2027247%2C2027255%2C2027288%2C2027306%2C2027322%2C2027332%2C2027333%2C2028266%2C2028292%2C2028319%2C2028526%2C2028870%2C2028876%2C2028882%2C2029062%2C2029309%2C2029414%2C2029422%2C2029428%2C2029447%2C2029732%2C2029785%2C2029793%2C2029813%2C2029899%2C2031028%2C2031457%2C2032039%2C2033610%2C2033854%2C2034498%2C2034628%2C2034978%2C2035966%2C2036668%2C2036905%2C2036930
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-46/
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-48/
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-50/
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-51/