What’s Vulnerable › Vulnerabilities

CVE-2025-8028: Large branch table could lead to truncated instruction

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2025-07-22 · updated 2026-10-05
• Weakness: CWE-1332

Description

On arm64, a WASM `br_table` instruction with a lot of entries could lead to the label being too far from the instruction causing truncation and incorrect computation of the branch address. This vulnerability was fixed in Firefox 141, Firefox ESR 115.26, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.

Affected products

• Mozilla Firefox: before 115.26.0; before 141.0; from 128.0 before 128.13.0; from 140.0 before 140.1.0 — fixed in 115.26.0, 128.13.0, 140.1.0, 141.0
• Mozilla Thunderbird: before 128.13.0; before 141.0; from 140.0 before 140.1.0 — fixed in 128.13.0, 140.1.0, 141.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 115.26.0, 128.13.0, 140.1.0, 141.0; Mozilla Thunderbird 128.13.0, 140.1.0, 141.0. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1971581
• https://www.mozilla.org/security/advisories/mfsa2025-56/
• https://www.mozilla.org/security/advisories/mfsa2025-57/
• https://www.mozilla.org/security/advisories/mfsa2025-58/
• https://www.mozilla.org/security/advisories/mfsa2025-59/
• https://www.mozilla.org/security/advisories/mfsa2025-61/
• https://www.mozilla.org/security/advisories/mfsa2025-62/
• https://www.mozilla.org/security/advisories/mfsa2025-63/
• https://lists.debian.org/debian-lts-announce/2025/07/msg00016.html

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