GHSA-88Q9-CMP2-C2VQ

oxidize-pdf: NaN/inf bypass in colour content-stream emission causes PDF rejection (DoS)

oxidize-pdf defines Color as a pub enum with public tuple-struct variants Rgb(f64, f64, f64), Gray(f64), and Cmyk(f64, f64, f64, f64). The constructors Color::rgb, Color::gray, and Color::cmyk clamp incoming
components to [0.0, 1.0], but because the variants are pub, callers can construct values directly without going through the constructors:

let safe   = Color::rgb(f64::NAN, 0.5, 0.5);   // clamps NaN to 0.0
let attack = Color::Rgb(f64::NAN, 0.5, 0.5);    // bypasses clamp

Color: Copy allows the non-finite value to propagate freely through API surfaces and serialisation. When such a value reaches a content-stream emitter, the writer formats it via format!("{:.3}", v). The Rust standard library renders
f64::NAN as "NaN", f64::INFINITY as "inf", and f64::NEG_INFINITY as "-inf", none of which are valid PDF numeric tokens per ISO 32000-1 §7.3.3:

▎ A numeric object shall be represented by one or more decimal digits with an optional sign and a leading, trailing, or embedded PERIOD.

The resulting content stream contains an invalid token sequence (e.g. NaN 0.500 0.500 rg). Conformant PDF viewers (Adobe Acrobat, Foxit, PDF.js, Apple Preview) reject the content stream, the affected page, or the entire document
depending on parser strictness.

Affected packages (all listed in the "Affected products" section of this advisory):

- oxidize-pdf on crates.io, the core Rust library where the vulnerable code path lives.
- OxidizePdf.NET on NuGet, .NET FFI binding that exposes Color through its public API; inherits the vulnerability from its dependency on oxidize-pdf.
- oxidize-pdf on PyPI, Python bindings (PyO3) that similarly expose colour construction; inherits the vulnerability from its dependency.

Who is impacted: any application that uses these packages to generate PDFs and accepts user-influenced colour values without validation. The most exposed surfaces are server-side PDF generators that take arbitrary f64 colour
parameters from upstream services.

Reproduction (Rust API):
use oxidize_pdf::{Document, Page, graphics::Color};

let mut doc = Document::new();
let mut page = Page::a4();
let gc = page.graphics();
gc.set_fill_color(Color::Rgb(f64::NAN, 0.5, 0.5));
gc.rectangle(50.0, 50.0, 100.0, 100.0).fill();
doc.add_page(page);
doc.save("malformed.pdf").unwrap();

// The resulting content stream contains:
//   NaN 0.500 0.500 rg
//   50 50 100 100 re
//   f
// which conformant viewers reject.

Affected sites in oxidize-pdf 2.5.7 (the same code paths are reached by both .NET and Python bindings via FFI):

- oxidize-pdf-core/src/text/flow.rs (TextFlowContext)
- oxidize-pdf-core/src/text/mod.rs (TextContext::apply_text_state_parameters)
- oxidize-pdf-core/src/graphics/mod.rs (GraphicsContext::apply_fill_color / apply_stroke_color)
- oxidize-pdf-core/src/graphics/patterns.rs (create_checkerboard_pattern / create_stripe_pattern / create_dots_pattern)
- ~45 sibling sites across forms/*, annotations/*, layout/rich_text.rs, and writer/pdf_writer/mod.rs that emit colour through the same code path.

Patches

The fix introduces a sanitising helper at the emission boundary in graphics/color.rs:

pub(crate) fn finite_or_zero(val: f64) -> f64 {
    if val.is_finite() { val } else { 0.0 }
}

Every colour-operator emitter (~50 sites across 17 files) now routes through fill_color_op / stroke_color_op / write_fill_color / write_stroke_color, which apply finite_or_zero before formatting. Non-finite components are substituted
with 0.0, so the wire format remains ISO 32000-1 conformant regardless of the input.

Patched releases:

- oxidize-pdf 2.6.0 on crates.io, contains the fix at the source.
- OxidizePdf.NET on NuGet, bumped to depend on oxidize-pdf 2.6.0 (see "Patched versions" above).
- oxidize-pdf on PyPI, bumped to depend on oxidize-pdf 2.6.0 (see "Patched versions" above).

Users should upgrade to the patched version of whichever package(s) they consume.

Workarounds

For users who cannot upgrade immediately:

- Always construct colours via the safe constructors Color::rgb(), Color::gray(), Color::cmyk(), which clamp components to [0.0, 1.0] (no NaN/inf survives clamping).
- Never use direct enum construction (Color::Rgb(...), Color::Gray(...), Color::Cmyk(...)) when components originate from untrusted input. The same applies to the corresponding APIs in the .NET and Python bindings.
- Validate untrusted f64 colour inputs with f64::is_finite() (Rust) or equivalent checks (!double.IsFinite(v) in .NET, math.isfinite(v) in Python) before passing them to any oxidize-pdf API.

These mitigations are partial, they cover the application layer but not other code paths that may construct Color values internally. The full fix is the upgrade to the patched versions.

References

- Issue: https://github.com/bzsanti/oxidizePdf/issues/220
- Companion refactor: https://github.com/bzsanti/oxidizePdf/issues/221
- Fix PR: https://github.com/bzsanti/oxidizePdf/pull/225
- Release PR (oxidize-pdf 2.6.0): https://github.com/bzsanti/oxidizePdf/pull/226
- .NET binding repository: https://github.com/bzsanti/oxidize-pdf-dotnet
- Python binding repository: https://github.com/bzsanti/oxidize-python
- ISO 32000-1 §7.3.3 (Numeric Objects): https://www.iso.org/standard/51502.html

A broader follow-up tracks the same CWE class in non-colour numeric content-stream emitters (line widths, transformation matrices, dash arrays, text positioning, path operators), to be addressed in oxidize-pdf 2.7.0 with its own
advisory.

The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.

GHSA-88Q9-CMP2-C2VQ has a CVSS score of 4.3 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.6.0, 0.8.0, 0.5.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is GHSA-88Q9-CMP2-C2VQ? GHSA-88Q9-CMP2-C2VQ is a medium-severity improper input validation vulnerability in oxidize-pdf (rust), affecting versions <= 2.5.7. It is fixed in 2.6.0, 0.8.0, 0.5.0. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
2. How severe is GHSA-88Q9-CMP2-C2VQ? GHSA-88Q9-CMP2-C2VQ has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by GHSA-88Q9-CMP2-C2VQ?
   • oxidize-pdf (rust) (versions <= 2.5.7)
   • OxidizePdf.NET (nuget) (versions <= 0.7.1)
4. Is there a fix for GHSA-88Q9-CMP2-C2VQ? Yes. GHSA-88Q9-CMP2-C2VQ is fixed in 2.6.0, 0.8.0, 0.5.0. Upgrade to this version or later.
5. Is GHSA-88Q9-CMP2-C2VQ exploitable, and should I be worried? Whether GHSA-88Q9-CMP2-C2VQ is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether GHSA-88Q9-CMP2-C2VQ is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix GHSA-88Q9-CMP2-C2VQ?
   • Upgrade oxidize-pdf to 2.6.0 or later
   • Upgrade OxidizePdf.NET to 0.8.0 or later
   • Upgrade oxidize-pdf to 0.5.0 or later