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TI-2026-51876 Aliases CVE-2026-73863

NanoMQ: Heap-Buffer-Overflow in `nmq_subinfo_decode()` During MQTT v5 SUBSCRIBE Parsing

Priority MEDIUM 64CWE-125Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
None
Impact type
—
Confidentiality · integrity · availability
None · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA.

Summary

NanoMQ is an MQTT broker. Prior to 0.24.14, NanoMQ's broker-side MQTT v5 nmq_subinfo_decode() function in nng/src/sp/protocol/mqtt/mqtt_parser.c reuses len_of_varint from the outer Properties Length while parsing each SUBSCRIPTION_IDENTIFIER. A remote client can send a SUBSCRIBE packet with a multi-byte Properties Length and repeated subscription identifiers, causing get_var_integer() to begin at an incorrect offset and read beyond the heap message buffer. The flaw is reachable through the broker receive path and can crash the broker, while the separately reported topic-option off-by-one occurs later and is not this vulnerability. This issue is fixed in version 0.24.14.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00353 29th percentileScored 2026-11-07
Fix Fixed nanomq (nanomq): 0.24.14

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
nanomqnanomqbefore 0.24.140.24.14Patch availableCNA
  • nanomq Vendornanomq Affected before 0.24.14 Fixed in 0.24.14 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:emqx:nanomq:*:*:*:*:*:*:*:*——nanomq
  • cpe:2.3:a:emqx:nanomq:*:*:*:*:*:*:*:* Versions — — ·nanomq

Remediation

  • Fix · CNA nanomq (nanomq) Fixed in 0.24.14

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-73863

References

Other 4

  • TI-2026-24672 NanoMQ has Heap Buffer Overflow in URI Parameter Parsing CVSS 4.0HIGH 7.7
  • TI-2024-28570 An access control issue in NanoMQ v0.21.10 allows attackers to bypass security… CVSS 3.1HIGH 8.8
  • TI-2026-27853 An issue in EMQ NanoMQ v.0.24.9 allows a remote attacker to cause a denial of service via… CVSS 3.1HIGH 7.5
  • TI-2026-17589 MQTT v5 Variable Byte Integer parsing out-of-bounds: get_var_integer() CVSS 3.1HIGH 7.5
  • TI-2024-20452 Null Pointer Dereference vulnerability in topic_filtern function in mqtt_parser.c in… CVSS 3.1HIGH 7.5
  • TI-2023-17307 NanoMQ 0.16.5 is vulnerable to heap-use-after-free in the nano_ctx_send function of nmq_mqtt.c. CVSS 3.1HIGH 7.5
See all 52 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences