Summary
Open Babel has out-of-bounds write (overlapping memcpy) in zipstream basicunzipstreambuf::underflow
A memory-safety vulnerability in Open Babel's bundled zipstream
decompression code caused an out-of-bounds write via overlappingmemcpy when reading a crafted gzip-compressed chemistry file.
Details
The flaw was in basic_unzip_streambuf::underflow. The decompression
buffer refill path invoked memcpy with overlapping source and
destination regions, which is undefined behavior and produced
out-of-bounds writes in practice. Any file format read through the
gzip-wrapped reader was a potential trigger.
Affected versions
All releases up to and including 3.1.1.
Patched version
3.2.0 (released 2026-05-26).
Credit
Reported via OSS-Fuzz.
Impact
Open Babel is a C++ library and CLI used to read and write chemistry
file formats; it is shipped by Linux distributions and embedded in
services that may parse untrusted input. Triggering this vulnerability
requires the victim to open a malicious gzip-compressed chemistry file
with the obabel tool, the OBConversion API, or any of the language
bindings (Python, Ruby, Java, R, Perl, C#, PHP).
A write operation targets a memory location beyond the intended buffer boundary. Typical impact: memory corruption, crash, or arbitrary code execution.
CVE-2025-10995 has a CVSS score of 7.8 (Low). The vector is requires local access, 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 (3.2.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Fix commit: https://github.com/openbabel/openbabel/commit/d4621d41
Originally reported as #2832; fixes consolidated in #2913.
A minimized reproducer for this CVE is checked in undertest/files/fuzz_regress/ and is exercised on every CI build under
ASAN+UBSAN by the fuzzregresstest harness.
Frequently Asked Questions
- What is CVE-2025-10995? CVE-2025-10995 is a low-severity out-of-bounds write vulnerability in openbabel (pip), affecting versions < 3.2.0. It is fixed in 3.2.0. A write operation targets a memory location beyond the intended buffer boundary.
- How severe is CVE-2025-10995? CVE-2025-10995 has a CVSS score of 7.8 (Low). 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.
- Which versions of openbabel are affected by CVE-2025-10995? openbabel (pip) versions < 3.2.0 is affected.
- Is there a fix for CVE-2025-10995? Yes. CVE-2025-10995 is fixed in 3.2.0. Upgrade to this version or later.
- Is CVE-2025-10995 exploitable, and should I be worried? Whether CVE-2025-10995 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
- What actually determines whether CVE-2025-10995 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.
- How do I fix CVE-2025-10995? Upgrade
openbabelto 3.2.0 or later.