Apple products are well-known for strong security. However, even Apple apps sometimes have severe bugs. Early in 2025, a new security issue was discovered: CVE-2025-46316. This bug allowed attackers to crash the Pages app—or even read sensitive process memory—by tricking users into opening a malicious document. Apple acted fast, but let’s break down what happened, how it worked, and what developers (and users) need to know.

What Is CVE-2025-46316?

CVE-2025-46316 is an out-of-bounds read vulnerability inside Apple Pages—a popular word processor included on macOS, iOS, and iPadOS devices. When Pages received a document with specifically crafted data, it could be tricked into reading memory outside the area where it was supposed to. This could crash the app or leak information from memory.

macOS: Versions before Tahoe 26.1 (fixed in 26.1)

Apple’s security note:
> Processing a maliciously crafted Pages document may result in unexpected termination or disclosure of process memory.
(Apple Security Advisories)

How Out-of-Bounds Read Bugs Work

If a program tries to read data from outside its own allocated chunk of memory—either before or after—the program could:

Crash (cause a segmentation fault)

- Leak memory contents: Unintentionally include private data like passwords, credentials, or document fragments that should not be visible

Here’s a simplified C-like example showing how this kind of bug can happen

// BAD: Out-of-bounds read if length is not validated!
void processDocumentChunk(uint8_t *data, size_t length) {
    uint32_t itemCount = data[]; // First byte tells us how many items follow
    for (uint32_t i = ; i < itemCount; i++) {
        uint8_t value = data[1 + i];
        // (do something with value)
    }
}

What’s Wrong Here?

If itemCount is greater than (length - 1), the loop will read memory past the buffer. The attacker could craft a file where itemCount is set high, making the loop leak memory it should never touch.

Exploiting CVE-2025-46316 in Pages

Attackers could make a special .pages document file that tells Pages to process more data than is actually inside the file, causing Pages to read memory outside the legitimate document’s area. This triggers:

Crash: The app terminates, probably showing a generic error.

2. Memory Disclosure: In some cases, fragments of process memory—potentially including user data or document snippets—could be accessed by the attacker if the memory is somehow returned in an error report, or included in auto-saved/crash files.

While there’s no evidence this bug let attackers run code directly, leaking memory can help with more serious attacks, or even expose user information by accident.

While publishing a working exploit is risky and unethical, a *safe* proof-of-concept might show

# Make a .pages file with a bad header that triggers out-of-bounds read

with open("crashme.pages", "wb") as f:
    f.write(b"PGES")          # Fake file magic
    f.write(bytes([255]))     # Fake item count (very high)
    f.write(b"\x00" * 10)     # Very little real content
# Open with old Pages versions to trigger (crash or leak)

*Note:* Real Pages files are much more complex, but the idea is the same: trick the program into reading past data it owns.

Check: Added code to make sure the file never claims to have more data than is actually present.

- Validation: Review count fields, header values, and offsets inside document structures before accessing memory.

A protected version might look like

void processDocumentChunk(uint8_t *data, size_t length) {
    if (length < 1) return;
    uint32_t itemCount = data[];
    if (itemCount > (length - 1)) {
        // Item count too high, reject the file
        return;
    }
    for (uint32_t i = ; i < itemCount; i++) {
        uint8_t value = data[1 + i];
        // Safe, within bounds
    }
}

How To Stay Safe

Users:
- Make sure your Pages, iOS/iPadOS, and macOS are updated—at least Pages 15.1, iOS/iPadOS 26.1, macOS Tahoe 26.1.
- Be very careful before opening any Pages documents received via email or internet, especially from new or unknown sources.

Developers:

Always validate input lengths, counts, and offsets!

- Use the right tools: memory safety checkers, fuzzers, and sanitizers can all catch out-of-bounds reads before release.
- Security bugs like this are usually found by experts: reward security researchers and encourage responsible disclosure.

References & Further Reading

- Apple Security Updates for June 2025
- CVE-2025-46316 at NVD (Placeholder, may not be live yet)
- Common Exploitation Patterns: Out-of-bounds Read (CWE-125)
- Understanding Memory Safety in C/C++
- Apple Pages Official Site

Conclusion

CVE-2025-46316 is a classic out-of-bounds read. It shows the risk from even well-tested, popular apps like Apple Pages. Fixes require strict input validation—never trust file fields blindly! Update your devices, follow secure coding guidance, and you’ll help keep your devices and software safe.

If you want to keep up with new bugs and Apple updates, check out Apple’s official security page or the NVD CVE database. Stay safe!

Timeline

Published on: 01/28/2026 17:26:19 UTC
Last modified on: 04/02/2026 19:21:06 UTC