CVE-2026-58465
Eclipse Wakaama before snapshot/2026-05-26 contains an unbounded memory allocation vulnerability in the CoAP Block1 handler within coap/block.c that allows unauthenticated remote attackers to exhaust server memory by sending a sequence of Block1 PUT…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.92%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
Eclipse Wakaama before snapshot/2026-05-26 contains an unbounded memory allocation vulnerability in the CoAP Block1 handler within coap/block.c that allows unauthenticated remote attackers to exhaust server memory by sending a sequence of Block1 PUT requests with incrementing block numbers. Attackers can target the registration endpoint over UDP without authentication, causing the server to repeatedly reallocate a growing accumulation buffer by appending each block payload without enforcing any maximum total size limit, resulting in denial of service through memory exhaustion.
- CVSS 4.0
- 8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.92% probability · 58th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Source
- disclosure@vulncheck.com
References
- https://github.com/eclipse-wakaama/wakaama/commit/a83f1ca28fa090fbc03c3669fef40daf4f89cd03
- https://github.com/eclipse-wakaama/wakaama/pull/881
- https://github.com/eclipse-wakaama/wakaama/releases/tag/snapshots%2F2026-05-26
- https://www.vulncheck.com/advisories/eclipse-wakaama-coap-block1-handler-unbounded-memory-allocation-dos
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.