Added opt-in bitonal (1-bit CCITT Group 4) image compression through AdvancedCompressionOptions for smaller and sharper scanned PDFs.
Added support for digitally signing an existing named signature field using PdfSignature.SignatureFieldName.
Added configurable Table of Contents titles and optional title entries through ChromePdfRenderOptions.
Improved tagged PDF handling when merging, importing, or securing PDFs; PDF/UA structure, document language, and accessibility metadata are now preserved for copied content.
PdfDocument now supports adding one digital signature at a time; attempting to add a second signature to the same document throws an exception. To add multiple signatures, sign and save the document, reopen it, and then add the next signature.
Updated internal dependencies.
修复
Fixed an issue where RenderHtmlAsPdfUA could incorrectly mark a wrapped paragraph and following content as artifacts, causing meaningful text to be hidden from assistive technologies.
Fixed an issue where converting PDFs containing emoji or other transparent content to PDF/A-1 could retain unsupported transparency and fail PDF/A-1b validation.
Fixed an issue where PDF/UA output could lose the required PDF/UA identification metadata in XMP.
Fixed an issue where PDF/UA conversion could cause images to disappear after a page was resized.
Fixed an issue where saving merged documents as PDF/UA could produce content that strict PDF readers could not decode.
Fixed an issue where signing PDFs could create duplicate AcroForm signature field names; affected signatures are now reported with a warning during verification.
Fixed an issue affecting PDF processing on macOS Apple Silicon deployments.
Fixed an issue where a failed PdfDocument constructor could cause an unrelated open document to be closed.
Fixed intermittent crashes when PDF documents were accessed concurrently.
IronPDF for Python 2026.6.0.12026年5月26日
功能
Added AdvancedCompressionOptions for fine-grained PDF compression control, including image DPI downsampling, JPEG quality settings, structure-tree removal, and customizable optimization flags.
Added PdfDocument.SetFormFont, SetFormFontFromFile, and DisableFormFontFallback APIs to control or suppress automatic form-field font embedding.
Added ECDSA PDF signature support with correct SHA/OID mappings for reliable verification and signing of EC-signed PDFs.
Updated internal dependencies.
修复
Fixed invisible or missing headers and footers on scanner-generated and browser-printed PDFs.
Fixed an issue where CopyPages could drop form fields with shared widget annotations across multiple pages, causing visible fields to disappear in copied documents.
Fixed incorrect Table of Contents page numbers for long headings that wrapped across multiple rendered lines.
Fixed excessive PDF size growth when combining static content headers/footers with dynamic content in large documents.
Fixed IronPdfEngine queue deadlocks under concurrent load.
IronPDF for Python 2026.4.0.1主版本2026年3月31日
功能
Improved PDF rendering performance by reducing internal render calls and reusing browser tabs to minimize startup overhead.
Improved PDF/UA structure tree tagging for forms with mixed input types, hidden elements, deeply nested labels, and annotation ordering to ensure correct widget-to-structure element association.
Improved IronPdfEngine Docker image security by removing unnecessary packages, resolving 4 high-severity CVEs and over 1,400 other security scan findings.
Improved IronPdfEngine Docker container to correctly forward runtime arguments like port, license_key, and chrome_browser_limit.
Reduced IronPdfEngine Docker image size by 60% (from 2.89 GB to 1.14 GB).
修复
Fixed memory leak in ReplaceTextOnPages, ReplaceUnicodeText, RedactText, and RedactRegions where repeated calls caused increasing memory growth (93-97% reduction).
Fixed buffer over-read in GetMetadata that could cause crashes or data corruption.
Fixed an issue where PDF/UA conversion removed CSS overflow:hidden clipping, ensuring clipped images render identically to standard PDF output.
Fixed an issue where SignatureName was always empty when verifying signatures created by external signers such as Adobe Reader.
Fixed missing header/footer images in DOCX to PDF conversion (DrawingML and VML).