OTP: Improper Handling of Exceptional Conditions
CVE-2026-42792 is a high-severity improper handling of exceptional conditions vulnerability in OTP from Erlang, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 865d203e4a6a8f44179eced9e1428f9259e4a3bb as the first without the flaw, so updating OTP to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.46% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update OTP to 865d203e4a6a8f44179eced9e1428f9259e4a3bb or a later version.
- Update Erlang/otp to 27.3.4 or 28.5.0.4 or 29.0.4, whichever matches your release line, or a later version.
- Update Erts to 15.2.7.11 or 16.4.0.4 or 17.0.4, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Erlang | OTP | 17.0 and later; 6.0 and later; 07b8f441ca711f9812fad9e9115bab3c3aa92f79 up to, but not including, 865d203e4a6a8f44179eced9e1428f9259e4a3bb | 865d203e4a6a8f44179eced9e1428f9259e4a3bb |
| Erlang | Erlang/otp | 17.0 up to, but not including, 27.3.4; 28.0 up to, but not including, 28.5.0.4; 29.0 up to, but not including, 29.0.4 | 27.3.4, 28.5.0.4, 29.0.4 |
| Erlang | Erts | 6.0 up to, but not including, 15.2.7.11; 16.0 up to, but not including, 16.4.0.4; 17.0 up to, but not including, 17.0.4 | 15.2.7.11, 16.4.0.4, 17.0.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 6.3 | Medium | CNA |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
Improper Handling of Exceptional Conditions vulnerability in Erlang OTP erts (epmd) allows an unauthenticated remote attacker to permanently terminate the Erlang Port Mapper Daemon (epmd) via connection slot exhaustion. The do_accept function in erts/epmd/src/epmd_srv.c calls epmd_cleanup_exit() when accept(2) returns EMFILE (per-process file descriptor limit reached) or ENFILE (system-wide file descriptor limit reached), rather than treating these as recoverable conditions. An attacker can exhaust epmd's file descriptor slots by holding many TCP connections open while periodically sending a single byte to reset the idle timeout, then causing accept(2) to return EMFILE, which kills the daemon. epmd has no per-source-IP connection cap, making the attack feasible from a single source. On Debian/Ubuntu default packaging the impact is amplified: the systemd unit inherits a low file descriptor soft limit, and repeated daemon deaths trigger systemd's start-rate-limit, permanently failing both epmd.service and epmd.socket and requiring manual operator intervention to recover. This issue affects OTP from OTP 17.0 before OTP 27.3.4.15, OTP 28.5.0.4, and OTP 29.0.4, corresponding to erts from 6.0 before 15.2.7.11, 16.4.0.4, and 17.0.4.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Exceptional Conditions
The product does not handle or incorrectly handles an exceptional condition.
More Improper Handling of Exceptional Conditions vulnerabilities (CWE-755)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- cna.erlef.org/cves/CVE-2026-42792.htmlThird Party Advisory
- github.com/erlang/otp/commit/07b8f441ca711f9812fad9e9115bab3c3aa92f79
- github.com/erlang/otp/commit/865d203e4a6a8f44179eced9e1428f9259e4a3bb
- osv.dev/vulnerability/EEF-CVE-2026-42792Third Party Advisory
- erlang.org/doc/system/versions.html#order-of-versionsRelease Notes
Other vulnerabilities in OTP
- 8.2 High severity
- 9.3 Critical severity
- 7.1 High severity
- 8.2 High severity
- 8.2 High severity
- 8.7 High severity
Recent Improper Handling of Exceptional Conditions vulnerabilities
- 8.4 High severity
- 8.8 High severity
- 8.7 High severity
- 7.5 High severity
- 7.5 High severity
- 7.3 High severity
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