CVE
CVE-2026-29078
Integer Underflow in Lexbor ISO‑2022‑JP Encoder
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->bufferused -= size with a stale size = 3 causes an integer underflow that wraps to SIZEMAX. 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.
Package Versions Affected
Package Version
patch Availability
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CVSS Version
Severity
Base Score
CVSS Version
Score Vector
C
H
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8.2
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4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
C
H
U
0
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C
H
U
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Related Resources
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References
https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/29xxx/CVE-2026-29078.json, https://github.com/lexbor/lexbor/security/advisories/GHSA-mrwr-xh7f-96v3, https://nvd.nist.gov/vuln/detail/CVE-2026-29078
Basic Information
Ecosystem
