CVE-2025-29911 is a critical (CVSS 9.8) heap buffer overflow in NASA CryptoLib 1.3.3 and earlier. The Crypto_AOS_ProcessSecurity function mishandles an AOS frame that is too short when it reads the frame error control field. The advisory lists no patched release, so check it for the fix.
What's affected
The record and the project advisory list NASA CryptoLib versions 1.3.3 and prior as affected. CryptoLib is a software only implementation of the CCSDS Space Data Link Security Protocol, Extended Procedures (SDLS-EP), used to secure links between a spacecraft running the core Flight System (cFS) and a ground station.
The advisory page I reviewed shows no patched release version. The record links to a fix commit for some of these issues, but a commit is not a release. Check the CryptoLib releases page and the advisory for the first fixed release before you decide that you are covered.
The record does not flag this CVE as known exploited (not in the CISA KEV catalog at the time of writing).
How to check if you're exposed
CryptoLib is usually built from source and linked into flight or ground software, so there may be no package manager entry to query.
- Search your build tree and your software bill of materials for CryptoLib, and note the version or commit you build from.
- If you vendor the source, look at the git history for the project's fix commit and see whether it is included in your tree.
- List every program that links the library and receives frames from a radio link, simulator or test harness.
Safeguard's free in-browser dependency scan at gold.safeguard.sh/scan can show whether a project's dependency list includes an affected component, and the Gold directory lets you look up the CVE and its related weaknesses.
What to do now
- Find every build that includes CryptoLib 1.3.3 or earlier, including ground segment tools and test benches.
- Check the CryptoLib advisory and releases for a fixed version, or for the fix commit referenced in the record, and plan the update.
- Until you have a fix, validate frame length fields and header sizes in your own code before passing frames to CryptoLib, and drop frames that fail those checks.
- Run the affected components with the least privilege your platform allows, and keep them away from networks that untrusted parties can reach.
- Add fuzz tests for frame parsing to your pipeline, since the advisories describe issues found that way.
Why it matters
The record maps the flaw to CWE-122 (Heap-based Buffer Overflow) and CWE-787 (Out-of-bounds Write). According to the advisory, the code reads the frame error control field at a position based on the configured maximum frame size, without first checking that the frame actually received is that long.
A short frame therefore makes the code touch memory outside the buffer. The advisory says the result can be a crash, and that code execution is possible in principle. The common thread with sibling CryptoLib issues is trusting a length or size that the sender controls, or that the configuration assumes, instead of the number of bytes actually received.
The fix pattern is straightforward: compare the received length with the configured frame size before any indexed read. Until a fixed release is in your build, validate frame sizes before they reach CryptoLib.
Quick check
What kind of frame triggers this?
The advisory describes an AOS frame whose length is smaller than the configured maximum frame size. I am not repeating test inputs here.
Is this the same as CVE-2025-29909?
No. It is a different function and frame type, though the same product and the same family of length handling mistakes.
Sources
Last reviewed: 19 October 2026.
