CVE-2026-20270
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a
CVSS
8.6
High
EPSS
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KEV
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Exploit Today
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0-100
Published: Aug 5, 2026 · Last modified: Aug 5, 2026 · CWE-682
Not enough EPSS history yet.
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco IOS XE Software engineering team has conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20270 are related to incorrect calculation issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-682.
CVECVSSEPSSKEVRExploitTitleMod.
CVE-2026-107735.4 MED7.3%
——2The DHCPv4 client helper net_dhcpv4_msg_type_name() in subsys/net/lib/dhcpv4/dhcpv4.c indexes a static 8-element const char * name table after a faulty bounds check. The guard used msg_type <= sizeof(name) instead of msg_type <= ARRAY_SIZE(name); sizeof returns the byte size of the pointer array (32 on 32-bit, 64 on 64-bit targets) rather than the element count of 8, so message-type values from 9 up to that byte size pass the check and cause name[msg_type - 1] to read past the end of the array.
The msg_type value originates from the DHCP MESSAGE TYPE option, which is read as an unchecked raw byte from a received packet (net_pkt_read_u8) and passed unmodified into the lookup. A DHCP server, or any host able to inject a spoofed DHCP reply onto the client's link, can therefore drive the index out of bounds. The out-of-range slot yields a garbage const char * that is then dereferenced by a %s log conversion.
The lookup is reached only from a debug log statement (NET_DBG / LOG_DBG), so the out-of-bounds read is triggerable only when the DHCPv4 log module is built at DEBUG level (CONFIG_NET_DHCPV4_LOG_LEVEL_DBG), which is not the default configuration. When that condition holds, the result is an out-of-bounds read and a wild-pointer dereference: most likely a crash of the DHCP client (denial of service) and potentially disclosure of an adjacent pointer's contents through the log output. The fix replaces sizeof with ARRAY_SIZE, restoring the correct 1..8 acceptance window.2dCVE-2026-472477.5 HIG36.8%
——11libheif is a HEIF and AVIF file format decoder and encoder. Prior to version 1.22.0, two bugs in libheif chain to leak process heap memory as visible pixel values in decoded grid images. An attacker who uploads a crafted AVIF/HEIC file to any server-side image processor (WordPress, Sharp/libvips, ImageMagick, etc.) can recover heap data - including library function pointers sufficient to defeat ASLR, or any other secret - from the publicly-downloadable transcoded JPEG/PNG/WebP output. Local attack vectors are also possible. Version 1.22.0 fixes the issue.9dCVE-2026-163639.8 CRI35.9%
——11JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.12dCVE-2026-555975.5 MED1.2%
——0ImageMagick is free and open-source software used for editing and manipulating digital images. Prior to version 7.1.2-26, an incorrect handling of arguments can cause a heap buffer over-write in the JP2 encoder. This issue has been fixed in version7.1.2-26.34dCVE-2026-440743.7 LOW25.5%
——8Netatalk 2.1.0 through 4.4.2 combines multiple errno values using bitwise OR, resulting in incorrect error codes when multiple error conditions occur simultaneously, which may allow a remote attacker to cause a minor service disruption via conditions that trigger incorrect error-handling paths.13dCVE-2026-78363.1 LOW17.3%
——5An incorrect calculation in the hextoint macro in Netatalk 2.0.0 through 4.4.2 due to improper uppercase character handling allows a remote authenticated attacker to cause limited data modification via crafted hexadecimal input.13d