OSV-2026-589 Heap-double-free in coap_new_oscore_conf
A heap double-free vulnerability in the CoAP library's OSCORE configuration parsing allows attackers to cause denial of service or potentially execute arbitrary code.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is OSV-2026-589?
OSV-2026-589 is an use after free vulnerability in libcoap, published on 19 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
OSS-Fuzz report: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=503812134
Crash type: Heap-double-free
Crash state:
coap_new_oscore_conf
oscore_conf_parse_target.c
coap_new_oscore_conf
Which versions are affected by OSV-2026-589?
1 open source package ship an affected version, including libcoap.
| Package | Affected | Fixed in |
|---|---|---|
libcoap OSS-Fuzz | All versions | None |
How do I fix OSV-2026-589?
No fix has been published for OSV-2026-589 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is OSV-2026-589 being exploited?
There is no known exploitation of OSV-2026-589 in the wild and no public exploit code.