CVE-2025-12829
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn uninitialized stack read issue exists in Amazon Ion-C versions <v1.1.4 that may allow a threat actor to craft data and serialize it to Ion text in such a way that sensitive data in memory could be exposed through UTF-8 escape sequences. To mitigate this issue, users should upgrade to version v1.1.4.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceAmazon Ion-C versions before v1.1.4 contain an uninitialized stack read vulnerability. An attacker can craft malicious data and serialize it to Ion text format, causing the library to read uninitialized stack memory contents and expose them through UTF-8 escape sequences in the output.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Locate the Ion-C library in your environmentSearch for libionc, ionc, or ionc.dll files; check package manager listings (e.g., pip list, npm ls, conan list); inspect linked binaries with ldd or dependency walkerAffected if The library is present and used by your application
-
Determine the installed Ion-C versionRun 'conan inspect <package> version' for Conan installations, check the ionc.h header for ION_VERSION macro, or query the library at runtime via ion_version() if exposedAffected if The version is below v1.1.4 (e.g., v1.1.3, v1.1.0, etc.)
-
Identify if Ion text serialization is usedSearch source code for IonTextWriter, ion_text_writer, or calls to ion_writer_make_text; grep for 'make_text_writer' or 'ION_TEXT' writer creation patternsAffected if Code creates text writers (as opposed to binary-only writers)
-
Inspect output for unexpected UTF-8 escape sequencesRun the serialization routine with controlled input and examine output for anomalous \uXXXX sequences not matching input data; monitor for information disclosure patternsAffected if Output contains UTF-8 escape sequences that do not correspond to the input data being serialized
You are affected if Amazon Ion-C version is below v1.1.4 AND your application uses Ion text serialization (IonTextWriter) to process untrusted data.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scopedUpgrade Amazon Ion-C to version v1.1.4 or later to remediate this vulnerability.
v1.1.4
- Identify the current Amazon Ion-C version in use
- Upgrade Amazon Ion-C to version v1.1.4 using the appropriate method for your installation (e.g., package manager, source compilation, or dependency update)
- Verify the upgrade was successful by checking the installed version matches v1.1.4
- Test that your application compiles and runs correctly with the updated library
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation2.0 h
- Testing8.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,352.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-12829 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2025-12829 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data