What’s Vulnerable › Vulnerabilities
CVE-2026-29078: Integer Underflow in Lexbor ISO‑2022‑JP Encoder
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-03-13 · updated 2026-06-17
- Weakness: CWE-191
Description
Lexbor is a web browser engine library. Prior to 2.7.0, the ISO‑2022‑JP encoder in Lexbor fails to reset the temporary size variable between iterations. The statement ctx->buffer_used -= size with a stale size = 3 causes an integer underflow that wraps to SIZE_MAX. Afterwards, memcpy is called with a negative length, leading to an out‑of‑bounds read from the stack and an out‑of‑bounds write to the heap. The source data is partially controllable via the contents of the DOM tree. This vulnerability is fixed in 2.7.0.
Affected products
- lexbor: before 2.7.0 — fixed in 2.7.0
How to fix
Upgrade to a fixed version: lexbor 2.7.0. Check the vendor advisory for mitigations.
References
Get alerted when CVE-2026-29078 or the next vulnerability affects your stack