CVE-2026-113783

High

Description

ESP-IDF is the Espressif Internet of Things (IOT) Development Framework. From 5.2.3 until 5.3.7, 5.4.5, 5.5.6, and 6.0.3, the lwIP DNS resolver's cached-lookup path in dns_lookup() in dns.c copies every cached address into a caller-provided single ip_addr_t output buffer without a length parameter or bounds check. When CONFIG_LWIP_DNS_MAX_HOST_IP is greater than 1 and a cached hostname has multiple A or AAAA records, a subsequent lookup through dns_gethostbyname() or dns_gethostbyname_addrtype() writes beyond the single-element buffer into adjacent stack memory. A network-positioned attacker who influences DNS responses can cause a reboot through stack-canary corruption or, without stack protection, overwrite stack variables with attacker-controlled address bytes and potentially redirect control flow. This issue is fixed in versions 5.5.6 and 6.0.3 and is scheduled to be fixed in versions 5.3.7 and 5.4.5. No fixed release is available for the end-of-life 5.2 line.

SeverityHigh
CVSS7.4
Exploit probability—
ProductEspressif Esp-idf
PublishedNov 4, 2026
First seenNov 4, 2026
Weakness typeCWE-121CWE-121

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
espressif esp-idf>= 5.2.3, <= 5.2.8, >= 5.3.2, < 5.3.7, >= 5.4.0, < 5.4.5, >= 5.5.0, < 5.5.6, >= 6.0.0, < 6.0.3—

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.

CVE-2026-113783 · Espressif Esp-idf · Dark Radar