🛡️ CVE-2021-43528 on Debian — thunderbird

⚪ Unknown ✅ No Known Exploit OSV

N/A

CVSS Score

0 Low4 Medium7 High9 Critical10

Description

Thunderbird unexpectedly enabled JavaScript in the composition area. The JavaScript execution context was limited to this area and did not receive chrome-level privileges, but could be used as a stepping stone to further an attack with other vulnerabilities. This vulnerability affects Thunderbird < 91.4.0.

Distribution advisory

This page covers CVE-2021-43528 as tracked by Debian, for the package thunderbird. The fix is available in version 1:91.4.0-1; earlier versions remain affected.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity high, availability none.

Affected software

DEBIAN-CVE-2021-43528 is recorded against 1 package.

thunderbird (fixed in 1:91.4.0-1)

Timeline and source

Published on 8 December 2021 and last revised on 4 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

security-tracker.debian.org (Advisory)

CVE-2021-43528 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Ubuntu

Details

Severity Unknown

CVSS Score N/A

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

CWE N/A

Public Exploit ✅ No

Source OSV

Published 2021-12-08

Updated 2026-08-12

Modified 2026-08-04

Fix URL N/A

Affected Packages

Software	From version	Fixed in
thunderbird	—	1:91.4.0-1

References

ADVISORY https://security-tracker.debian.org/tracker/CVE-2021-43528

🔗 NVD 🔗 Mitre

Similar Threats

Unknown ALSA-2022:8547
Unknown ALSA-2022:8561
Unknown ALSA-2022:7178
Unknown ALSA-2022:7190
Unknown ALSA-2022:7023

Free Vulnerability Check

Is your site affected by DEBIAN-CVE-2021-43528?

BotEraser helps you identify potentially vulnerable plugins and themes by checking your installation against DEBIAN-CVE-2021-43528 and other known CVE records.

Scan My Site Free →

No credit card required · Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.