Quick answers
- Is CVE-2026-113783 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-113783 being exploited in the wild.
- How severe is CVE-2026-113783?
- High severity, with a CVSS score of 7.4, published 4 November 2026.
- Which products and versions are affected?
- Espressif ESP-IDF 5.2.3 to 5.3.6, 5.4.0 to 5.4.4, 5.5.0 to 5.5.5, 6.0.0 to 6.0.2.
- Is there a fix for CVE-2026-113783?
- Yes: fixed in 5.3.7, 5.4.5, 5.5.6, 6.0.3. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-113783 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-113783?
- Check whether you run Espressif ESP-IDF at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: 5.3.7, 5.4.5, 5.5.6, 6.0.3
Technical details
The lwIP DNS resolver's cached-lookup path in dns_lookup() writes multiple cached addresses into a single-element ip_addr_t output buffer without bounds checking when CONFIG_LWIP_DNS_MAX_HOST_IP is greater than 1. A network-positioned attacker who influences DNS responses can overflow stack memory, corrupting the stack canary to cause reboot or overwriting stack variables to redirect control flow. The vulnerability requires the caller to use dns_gethostbyname() or dns_gethostbyname_addrtype() with a cached hostname that has multiple A or AAAA records.
Affected products
- Espressif ESP-IDF 5.2.3 to 5.3.6, 5.4.0 to 5.4.4, 5.5.0 to 5.5.5, 6.0.0 to 6.0.2
Timeline
- 2026-11-04: disclosed