Description
A NULL pointer dereference in libcoap v4.3.5-rc2 and below allows a remote attacker to cause a denial of service via the coap_handle_request_put_block function in src/coap_block.c.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | libcoap3 | 4.3.5-1 | — |
| Debian 13 | libcoap3 | No fix yet | — |
| Debian 12 | libcoap3 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | libcoap3 | No fix yet | — |
| Ubuntu 26.04 LTS | libcoap3 | No fix yet | — |
| Ubuntu 25.10 | libcoap3 | No fix yet | — |
| Ubuntu 24.04 LTS | libcoap3 | No fix yet | — |
| Ubuntu 22.04 LTS | libcoap2 +1 | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | libcoap2 | No fix yet | — |