Loop with Unreachable Exit Condition ('Infinite Loop') Affecting erlang-sasl package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-RHEL10-ERLANGSASL-17814308
- published4 Jul 2026
- disclosed2 Jul 2026
Introduced: 2 Jul 2026
NewCVE-2026-54886 (opens in a new tab)How to fix?
There is no fixed version for RHEL:10 erlang-sasl.
NVD Description
Note: Versions mentioned in the description apply only to the upstream erlang-sasl package and not the erlang-sasl package as distributed by RHEL.
See How to fix? for RHEL:10 relevant fixed versions and status.
Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in Erlang OTP ssh (ssh_sftpd module) allows an authenticated SFTP user to render an SFTP channel permanently unresponsive.
The handle_data/4 function in ssh_sftpd contains a catch-all clause that accepts channel data of any type. When channel data with a non-zero type code (SSH_MSG_CHANNEL_EXTENDED_DATA) arrives with an empty pending buffer and a payload at or below the SFTP packet size limit, the clause tail-calls itself with identical arguments, creating an infinite loop.
The SFTP protocol operates exclusively on normal channel data (type 0). Extended data (non-zero type) is meaningless for SFTP and is never sent by conforming clients. However, the SSH protocol permits any channel participant to send extended data on an open channel, so an authenticated SFTP client can trigger the loop by sending SSH_MSG_CHANNEL_EXTENDED_DATA with any data_type_code and any non-empty payload at or below the size limit.
The targeted ssh_sftpd process enters an infinite tail-recursive loop. It never processes another message, its message queue grows without bound, and it can only be stopped by killing the process. BEAM's reduction-based scheduler preemption continues to function, so other processes on the node are not starved, but each stuck channel process consumes its full CPU time share continuously and accumulates unbounded message queue memory. Opening many channels amplifies the CPU and memory impact.
Erlang/OTP SSH configurations using the default max_channels setting (infinity) allow an authenticated user to open unlimited channels per connection, amplifying the attack without requiring multiple TCP connections or authentications.
No file contents, credentials, or write access are obtainable through this issue. The impact is limited to denial of service on targeted SFTP channels, with secondary CPU degradation and memory growth.
This vulnerability is associated with program file lib/ssh/src/ssh_sftpd.erl and program routine ssh_sftpd:handle_data/4.
This issue affects OTP from OTP 17.0 until OTP 29.0.3, 28.5.0.3, and 27.3.4.14 corresponding to ssh from 3.0.1 until 6.0.2, 5.5.2.2, and 5.2.11.9.
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2496623
- https://access.redhat.com/security/cve/CVE-2026-54886
- https://cna.erlef.org/cves/CVE-2026-54886.html
- https://github.com/erlang/otp/commit/eaf9550b8ad4738b81149d3f617102d980c6dd18
- https://github.com/erlang/otp/security/advisories/GHSA-7wp4-pc27-2vj9
- https://osv.dev/vulnerability/EEF-CVE-2026-54886
- https://www.erlang.org/doc/system/versions.html#order-of-versions