CVE-2026-88361

Weakness

SumatraPDF 3.6.1 contains an integer overflow vulnerability in EngineMupdf::BuildPageLabelRec() when parsing PDF PageLabels /Nums entries.

References

• https://github.com/chenjiefeng2001/sumatrapdf_folked/commit/b22a8c71ddc9de80ece5f88d14b434c20fee912e
• https://github.com/haimag/sumatrapdf/commit/8b999ff1bf0a8df244e75440682a3fd9a038eb2d
• https://github.com/sumatrapdfreader/sumatrapdf/issues/5952