Skip to content
OpenAdvisories
High ALAS2-2026-4081 3 CVEs

Important: rclone security update (Amazon Linux 2)

Published Nov 9, 2026 · Updated Nov 9, 2026

Summary

Package updates are available for Amazon Linux 2 that fix the following vulnerabilities: CVE-2026-78659: When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicious client can exploit this by sending a "Trailer" header that declares a large number of fields causing the server to allocate a disproportionate amount of memory while bypassing Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits. This exploit is not applicable for HTTP/1 servers, which do not support multiplexing a large number of requests over one TCP connection, and whose Server.MaxHeaderBytes are calculated differently. Server.MaxHeaderValueCount and Server.MaxHeaderBytes limits are now applied towards the trailer fields declared in "Trailer" headers. NOTE: https://www.openwall.com/lists/oss-security/2026/10/08/9 NOTE: https://github.com/golang/go/issues/81857 NOTE: Fixed by: https://github.com/golang/go/commit/cbb0fb8b51cba866018b8a0fb4b5458f16c5c80b (go1.27.2) NOTE: Fixed by: https://github.com/golang/go/commit/6e049521882c944afc1e519a83971ec421dc2974 (go1.26.9) CVE-2026-116191: Rclone before 1.75.2 contains a path traversal vulnerability in serve webdav that allows unauthenticated attackers to write above the served root by sending an unvalidated '..' path component. Attackers can send MKCOL /.. to plant a VFS node, then PUT, MOVE, COPY, or MKCOL to create, overwrite, or delete files belonging to other tenants. CVE-2026-116189: rclone from 1.55.0 before 1.75.2 contains a signature verification bypass in stable selfupdate that trusts checksums from unsigned bytes preceding the PGP-clearsigned SHA256SUMS block. Attackers controlling the release distribution path can prepend an unsigned checksum line matching a malicious archive, causing selfupdate to install an attacker-controlled rclone executable.

Fixed packages 2

ReleasePackageFixed in
Amazon Linux · 2 rclone 0:1.55.1-1.amzn2.0.13
Amazon Linux · 2 rclone-debuginfo 0:1.55.1-1.amzn2.0.13

Vulnerabilities 3

  • High 7.5

    rclone 1.55.0 before 1.75.2 selfupdate Signature Verification Bypass via SHA256SUMS

    rclone from 1.55.0 before 1.75.2 contains a signature verification bypass in stable selfupdate that trusts checksums from unsigned bytes preceding the PGP-clearsigned SHA256SUMS block. Attackers controlling the release distribution path can prepend an unsigne…

  • High 7.5
    CVE-2026-116191 Public exploit

    Rclone before 1.75.2 Path Traversal via serve webdav MKCOL

    Rclone before 1.75.2 contains a path traversal vulnerability in serve webdav that allows unauthenticated attackers to write above the served root by sending an unvalidated '..' path component. Attackers can send MKCOL /.. to plant a VFS node, then PUT, MOVE, …

  • High 7.5

    HTTP/2 server memory exhaustion due to Trailer headers in net/http

    When "Trailer" headers are sent by a client, the HTTP server internally uses the header values to populate the Request.Trailer map passed to the server handler. Because Request.Trailer is a map, each entry incurs memory overhead. For HTTP/2 servers, a malicio…

References

  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-116189.html
  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-116191.html
  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-78659.html