CVE WatchOct 28, 2026

CVE-2026-111108

Apache Kafka's code-generated protocol readers pre-size an array's collection from the element count declared by the sender. That count is c

CVSS

—

No CVSS

EPSS

—

KEV

—

Exploit Today

—

0-100

Published: Oct 28, 2026 · Last modified: Oct 28, 2026 · CWE-400 · CWE-770 · CWE-789

EPSS · 30d

Not enough EPSS history yet.

Technical description

Apache Kafka's code-generated protocol readers pre-size an array's collection from the element count declared by the sender. That count is checked only against the bytes remaining in the request buffer, which assumes about one byte per element; because most elements need several bytes, a request can declare far more elements than the buffer holds and still pass. For a keyed array the reader then allocates an ImplicitLinkedHashCollection of capacity (2 * count +1), so a request of a few tens of megabytes can force a heap allocation several times larger before any element is read. The pattern is emitted into every generated reader, so it affects all Kafka API types with an array field. Impact: Request parsing happens before any authorization check. On a listener that does not require authentication (for example PLAINTEXT), an unauthenticated attacker can send a few concurrent requests that each declare a very large= array length and allocate many times their wire size in broker heap, crashing the broker with an OutOfMemoryError. The reporter demonstrated three concurrent ~90 MB ProduceRequest (v3) connections exhausting a 1 GB heap (~8x amplification). On listeners that require authentication, the attacker needs valid credentials but no specific ACL, since parsing precedes authorization.. Mitigation: Upgrade to Apache Kafka 4.2.2, 4.3.2, or 4.4.0. Until then, lowering socket.request.max.bytes and restricting network access to broker listeners reduces, but does not remove, exposure. Resolution: From Apache Kafka 4.2.2, 4.3.2, and 4.4.0: generated readers cap the initial array pre-allocation at MessageUtil.MAX_PREALLOCATED_ARRAY_CAPACITY (1000) and grow it on demand, and reject a declared array length above MessageUtil.MAX_ARRAY_LENGTH (1,000,000).

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-1186897.5 HIG

—

———OvenMediaEngine through 0.21.0 contains a denial of service vulnerability in OvtPacket::LoadHeader() that allows unauthenticated attackers to stall connections by sending payload_length values above 32750. Attackers can send crafted OVT packets to the OVT listener to hold connections open indefinitely and accumulate buffered memory, disrupting origin-to-edge stream relay.3h CVE-2026-118664—

—

———decode-uri-component provides a more robust alternative to decodeURIComponent. Prior to 0.5.1, decodeUriComponent in index.js falls back to customDecodeURIComponent after native decoding throws, and the fallback collects every distinct percent-encoded run before performing a full-string regular-expression replacement for each entry. Malformed input containing many distinct runs can therefore make both the number of replacements and the scanned input length grow together, causing quadratic CPU consumption and blocking the Node.js event loop; request-body inputs can reach the demonstrated size, while ordinary URL header limits reduce the practical delay. This issue is fixed in version 0.5.1.4h CVE-2026-118261—

—

———Echo is a Go web framework. From 4.0.0 until 4.16.1, Echo v4's opt-in Decompress middleware exposes a gzip-decoded request stream without limiting its expanded size. A small compressed request can expand into a very large body when a handler reads or binds it, consuming excessive memory or CPU and allowing repeated or concurrent requests to cause denial of service. The middleware is not enabled by default, and limiting only the compressed request size does not bound the decoded size. This issue is fixed in 4.16.1.6h CVE-2026-118260—

—

———Echo is a Go web framework. From 4.0.0 until 4.16.1, Echo v4's opt-in BodyDump middleware reads complete request bodies into memory before handlers run and retains complete response bodies for the dump callback without capture limits. An unauthenticated client that can reach a route using BodyDump can submit large bodies or influence large responses, causing repeated or concurrent allocations that exhaust process memory. BodyDump is not enabled by default, and external request limits may reduce request-side exposure but do not bound response capture. This issue is fixed in 4.16.1.6h CVE-2026-117501—

—

———HTTP::Body versions before 1.24_01 for Perl allow memory exhaustion via unbounded buffering of chunked request bodies. In chunked mode, used when no content length is given, add() holds each chunk in memory until all of it has arrived. A line that is not a chunk-size line, a size line without CRLF, or a size too large to fit an integer leaves the parser waiting forever, and every later add() grows the buffer. A remote attacker can exhaust memory in applications that pass chunked request bodies to HTTP::Body.7h CVE-2026-116273—

—

———MIME::Parser versions before 5.521 for Perl set no limit on the number of message parts by default, allowing memory exhaustion. The max_parts option defaulted to -1, which disables the limit, so a parser created with default settings builds an entity for every part however many a message has. Version 5.521 sets max_parts to 1000 and max_depth to 64 by default. Setting either to -1 still removes the limit.7h