CVE-2026-16411

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.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• 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

0.57% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 46.8% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

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

NVD analysis status

Modified. NVD last modified this record on 2026-10-21.

Red Hat severity

Important. 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

2026-07-21 12:38Z3 MO AGO

Last updated

2026-10-21 13:50Z8 DAYS AGO

Reserved

2026-07-20

Assigning CNA

mozilla

Record state

PUBLISHED

Severity

Critical (CVSS 9.8)

CNA CVSS vector

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

Weaknesses

• CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferClass

Data version

5.2

Document digest

c145bc3efe2b4f00943066edbc475d6673f446726b2b4d5257578f6c1ad63dd4

• bugzilla.mozilla.orgModerate-severity memory safety bugs fixed in Thunderbird 153https://bugzilla.mozilla.org/buglist.cgi?bug_id=1420800%2C1598946%2C1767921%2C2013993%2C2025417%2C2027325%2C2027364%2C2029433%2C2029807%2C2029901%2C2029922%2C2030102%2C2030563%2C2032110%2C2037801%2C2042756%2C2044625%2C2045609%2C2047920%2C2048491%2C2048492%2C2048800%2C2050534%2C2050662%2C2050871
• bugzilla.mozilla.orgLow-severity memory safety bugs fixed in Thunderbird 153https://bugzilla.mozilla.org/buglist.cgi?bug_id=2006467%2C2027346%2C2027349%2C2027353%2C2027362%2C2027371%2C2027373%2C2028954%2C2029694%2C2036906%2C2038964%2C2039460%2C2040522%2C2040834%2C2043275%2C2045394%2C2045606%2C2052060
• bugzilla.mozilla.orgHigh-severity memory safety bugs fixed in Thunderbird 153https://bugzilla.mozilla.org/buglist.cgi?bug_id=2048936%2C2049804
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-68/
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-71/