CVE-2026-103501 Memory corruption in Apache DataSketches
Heap buffer overflow in Apache DataSketches C++ allows attackers to corrupt memory and potentially execute code via crafted HLL sketches.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-103501?
CVE-2026-103501 is a critical memory corruption vulnerability in Apache DataSketches, published on 10 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Heap buffer overflow in the HLL sketch deserialization of Apache DataSketches C++ (repo: datasketches-cpp).
When deserializing a sketch in LIST mode, from either a byte buffer or a stream, the coupon count was read from the input and used as the number of entries to copy into a fixed buffer of 8 entries, without checking it against the buffer's capacity. A crafted sketch could cause a write of up to 988 bytes past the end of this internal heap buffer. This can corrupt heap memory, causing a crash and potentially enabling further exploitation.
This issue affects Apache DataSketches C++: from 1.0.0-incubating before 5.3.0. Only applications that deserialize HLL sketches from untrusted sources are affected.
Users are recommended to upgrade to version 5.3.0, which fixes this issue.
Which versions are affected by CVE-2026-103501?
How do I fix CVE-2026-103501?
No fix has been published for CVE-2026-103501 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-103501 being exploited?
There is no known exploitation of CVE-2026-103501 in the wild and no public exploit code.
Sources
Also known as GHSA-w656-xfm5-jqjh.