CVE-2026-74988

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

0.35% probability of exploitation activity in the next 30 days.

EPSS percentile

Ranks above 27.6% 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 2026-09-01.

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

2026-08-18 12:23Z17 DAYS AGO

Last updated

2026-09-01 21:25Z3 DAYS AGO

Reserved

2026-08-17

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

e73fcb20d4875c2eb16a6620a2b9a6bdcca49105689839b12fa4c04eb8ddb699

• bugzilla.mozilla.orgModerate Severity internally found bugs fixed in Thunderbird ESR 153.1 and Thunderbird 154https://bugzilla.mozilla.org/buglist.cgi?bug_id=2018164%2C2045404%2C2045507%2C2045711%2C2052403%2C2053174%2C2054643%2C2054667%2C2054671%2C2054674%2C2054687%2C2054717%2C2054761%2C2054787%2C2055676%2C2056779%2C2056781%2C2058629%2C2059019%2C2059138
• bugzilla.mozilla.orgHigh Severity internally found bugs fixed in Thunderbird ESR 153.1 and Thunderbird 154https://bugzilla.mozilla.org/buglist.cgi?bug_id=2045796%2C2046734%2C2051424%2C2054721%2C2057994%2C2058094%2C2058611%2C2058615%2C2058616%2C2061315
• bugzilla.mozilla.orgLow Severity internally found bugs fixed in Thunderbird ESR 153.1 and Thunderbird 154https://bugzilla.mozilla.org/buglist.cgi?bug_id=2053153%2C2053262%2C2054763%2C2059198%2C2059224
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-74/
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-77/
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-78/
• www.mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-80/