CVE WatchOct 22, 2026

CVE-2026-20019

Multiple Cisco products are affected by a vulnerability in the Snort 3 NetFlow Detection Engine that could allow an unauthenticated, remote

CVSS

5.8

Medium

EPSS

—

KEV

—

Exploit Today

—

0-100

Published: Oct 21, 2026 · Last modified: Oct 22, 2026 · CWE-835

EPSS · 30d

Not enough EPSS history yet.

Technical description

Multiple Cisco products are affected by a vulnerability in the Snort 3 NetFlow Detection Engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to incomplete error checking when Snort 3 parses UDP Netflow Protocol packets. An attacker could exploit this vulnerability by sending a single crafted Netflow packet through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a DoS condition.

Official references

sec.cloudapps.cisco.comhttps://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snort3-misc-dos-6mB22qAK

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-66281—

—

———In EmberZNet 9.1.1 and earlier, a malformed Discover Attributes command can result in a loop with unreachable exit condition (infinite loop). These messages must come from a device that has already joined the network. Only devices supporting manufacturer-specific clusters are impacted.6h CVE-2026-1103547.5 HIG

—

———HAProxy 3 before 3.4.6 allows a remote unauthenticated attacker to cause a denial of service (persistent worker-thread CPU exhaustion) via an HTTP/1.1 chunked request. Although the H1 multiplexer drains the request before closing the stream, the parser repeatedly re-processes the same bytes without making progress. The affected thread stays busy at 100% CPU after timeouts expire and after the client disconnects, and repeated requests can consume all worker threads until the process is restarted.18h CVE-2026-96642—

—

———Pillow is a Python imaging library. Prior to 13.0.0, the TarIO initializer in src/PIL/TarIO.py accepts a negative octal member size and computes a backward seek that returns to the same 512-byte header. When the requested member name does not match, the parser repeatedly reads that header, consumes a full CPU core, and never returns. TarIO is reached only when an application directly uses PIL.TarIO.TarIO rather than the default Image.open() path. This issue is fixed in version 13.0.0.1d CVE-2026-764455.3 MED

—

———Multiple Cisco products are affected by a vulnerability in the Snort 3 Detection Engine that could allow an unauthenticated, remote attacker to cause the detection engine to unexpectedly restart, resulting in a denial of service (DoS) condition. The vulnerability is due to a flaw in logic handling when General Packet Radio Service (GPRS) Tunneling Protocol (GTP) extension headers are processed within the codec. An attacker could exploit this vulnerability by sending a crafted, fragmented UDP datagram that contains these headers to the Snort 3 Detection Engine of an affected device. A successful exploit could allow the attacker to cause the detection engine to enter an infinite loop, resulting in a DoS condition.7h CVE-2026-113794—

—

———pypdf is a free and open-source pure-python PDF library. Prior to 6.20.0, an attacker can craft an incomplete PDF that ends inside a standard cross-reference table, causing pypdf to mishandle the unexpected end of file and enter an infinite loop. This issue is fixed in version 6.20.0.1d CVE-2026-113793—

—

———pypdf is a free and open-source pure-python PDF library. Prior to 6.20.1, removing an object from a crafted cyclic PDF tree, such as an outline item, can enter an infinite loop and block the current process. This issue is fixed in version 6.20.1.1d