CVE-2026-78066
Low risk· EPSS 5%Exploitation Probability (EPSS)
Low risk5th percentile - higher than 5% of all known CVEs
Summary
Resource exhaustion vulnerability in Apache bRPC versions before 1.18.0 affects multiple parsers that accept wire-controlled input. The gzip/zlib/snappy decompressors enforce no output limit, and the AMF, RTMP, sofa-pbrpc, and mcpack2pb parsers trust wire-declared sizes, allowing attackers to cause disproportionate memory use and crash the process.
Risk Assessment
An attacker can send a crafted request to a bRPC service, causing memory exhaustion and denial of service. The risk applies to any organization exposing bRPC services to untrusted clients.
Recommendation
Upgrade Apache bRPC to version 1.18.0 or apply the patch from PR #3476. After the fix, consider adjusting the -max_decompressed_body_size and max_body_size flags if larger values are legitimately required.
Other vulnerabilities in Apache bRPC
See all- CVE-2025-60021Critical
Remote command injection vulnerability in heap profiler builtin service in Apache bRPC (all versions < 1.15.0) on all platforms allows attacker to inject remote command. Root Cause: The bRPC heap profiler built-in service (/pprof/heap) does not validate the user-provided extra_options parameter and executes it as a command-line argument. Attackers can execute remote commands using the extra_options parameter. Affected scenarios: Use the built-in bRPC heap profiler service to perform jemalloc memory profiling. How to Fix: we provide two methods, you can choose one of them: 1. Upgrade bRPC to version 1.15.0. 2. Apply this patch ( https://github.com/apache/brpc/pull/3101 ) manually.
- CVE-2026-90484Low risk· EPSS 4%
The MySQL client response parser in Apache bRPC dereferences a null pointer when the server peer sends a zero-payload-length response packet. A packet with declared zero payload length passes the frame-length check, after which the parser reads the response type byte via an unbounded 5-byte fetch that returns nullptr, causing type = p[4] to dereference it and crash the client process.
- CVE-2026-87849Low risk· EPSS 5%
A vulnerability in the Discovery naming-service reply parser in Apache bRPC (versions < 1.18.0) calls RapidJSON object-only accessors (FindMember) on JSON values without first validating that they are objects. A malformed Discovery response whose data/service members or instances list contain non-object entries triggers an out-of-bounds read and potentially crashes the bRPC client.
- CVE-2026-86249Low risk· EPSS 24%
On a brpc::Server that sets both ServerOptions.auth and ServerOptions.internal_port, the HTTP built-in service exemption on internal_port can be abused to bypass authentication entirely. Verification runs only for the first message of a connection and the result latches the connection, so a request such as GET /status to internal_port authenticates the whole connection.
- CVE-2026-86147Low risk· EPSS 10%
Apache bRPC versions before 1.18.0 expose builtin /flags and /pprof services that allow a remote attacker to change dump paths (bvar_dump_file, bvar_dump_tabs, mbvar_dump_file) and create directories or overwrite files with the server process privileges. Additionally, the ?seconds= parameter in /pprof is not clamped, enabling an attacker to hold the process-wide CPU profiler for an arbitrarily long time.
- CVE-2026-86146Low risk· EPSS 10%
HTTP request/response smuggling vulnerability in Apache bRPC versions < 1.18.0 stems from inconsistent HTTP/1.1 header parsing in its bundled parser. bRPC accepts malformed header forms (space before colon, spaces in Content-Length values, obs-fold, chunked trailers merged as headers, Transfer-Encoding lists with whitespace), allowing attackers to smuggle requests or headers when bRPC is deployed behind a proxy or load balancer.
- CVE-2026-84748Low risk· EPSS 7%
Improper authorization in Apache bRPC (versions < 1.18.0) allows remote attackers to access builtin services through the public port. Protobuf-based protocol dispatch paths computed but did not enforce the security_mode flag, allowing invocation of services such as brpc.vars or hotspots.
- CVE-2026-84747Low risk· EPSS 11%
A vulnerability in Apache bRPC (versions < 1.18.0) stems from an interpretation conflict in HTTP path handling between bRPC and a front proxy. The FindMethodPropertyByURI() function skips empty path segments (consecutive slashes), so paths like //flags are dispatched as /flags, even though RFC 3986 treats them as distinct. Additionally, HTTP/2 does not validate the :path pseudo-header, allowing bypass of proxy ACL rules and access to internal services.
- CVE-2026-84727Medium
A use-after-free exists in the RTMP protocol implementation in Apache bRPC (version < 1.18.0). A malicious RTMP peer can crash the process or potentially corrupt memory via a crafted Abort message. The root cause is that the receive path deletes the target RtmpChunkStream object while the send path concurrently dereferences it without synchronization.
- CVE-2026-82953Low risk· EPSS 12%
A NULL pointer dereference in the RTMP protocol implementation in Apache bRPC (versions < 1.18.0) occurs when the server rejects a createStream request by returning a null stream and then fails to write the error response, causing a crash. A remote attacker can trigger a denial of service by sending a crafted createStream command and closing the connection before the rejection response is written.
Original NVD description (English source)
Resource exhaustion in Apache bRPC (version < 1.18.0) on all platforms: multiple parsers that accept wire-controlled input bound no limit on the sizes declared by the client or on decompressed output, which attackers can use to drive disproportionate memory use and crash the process. Root Cause: 1) The gzip/zlib/snappy decompressors enforce no output limit: -max_body_size is checked against the compressed bytes only, so a cap-compliant body (e.g. 64 MiB) can decompress to tens of GiB. 2) The AMF string readers allocate the declared length before the bytes are actually available. 3) RTMP chunk headers may re-declare a message length mid-stream; the declared length was never bounded and the partial reassembly buffer kept growing. 4) The sofa-pbrpc parser does not bound meta_size. 5) mcpack2pb trusts wire-declared item counts for Reserve() and a string value_size of 0 underflows the buffer size, aborting the process. Affected Scenarios: Any bRPC service accepting gzip/zlib/snappy-compressed bodies or rtmp, sofa-pbrpc, or mcpack2pb messages from untrusted clients. How to Fix:(Choose one of the following options) 1. Upgrade bRPC to version 1.18.0, which fixes this issue. 2. Apply this patch: https://github.com/apache/brpc/pull/3476 Note: After the fix, requests whose decompressed size, RTMP message length, or mcpack declared count exceed the new limits are rejected. Operators who legitimately need larger values can raise the corresponding flag (-max_decompressed_body_size, max_body_size).
Vulnerability data from NVD (NIST) · CISA KEV · EPSS

