CVE•Published 2026-07-22•Modified 2026-08-12•0 articles on news•6 live references•NVD data

CVE-2026-14899Mozilla · Thunderbird

Vulnerability data via NVD (ingested)

CVSS v3.1

7.5

HIGH

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

EPSS percentile

Exploit Prediction Scoring System · top 82% of all CVEs

Weaknesses (CWE)

CWE-193Off-by-one Error

Description

The code to parse MIME headers for display when forwarding a message (if the setting to view all headers was enabled) had an off-by-one error, allowing a single byte to be read from the memory after the buffer for the headers, and potentially crashing Thunderbird. This vulnerability was fixed in Thunderbird 153 and Thunderbird 140.13.

Timeline

Published 2026-07-22

Modified 2026-08-12

External references

NVD MITRE Exploit-DB GitHub PoC Sploitus VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-14899

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Mozilla Thunderbird"

All exposed Mozilla Thunderbird instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Thunderbird"

HTTP body or banner mentions "Thunderbird" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-14899