epmd permanent DoS via EMFILE on accept(2) in erts
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 29.0.4, OTP 28.5.0.4 and OTP 27.3.4.15.
- Published
- Jul 27, 2026
- Updated
- Aug 10, 2026
- EPSS
- 0.4% · 36th percentile
- CWE
- CWE-755
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Report tools
Action score
25
Monitor
Low priority for now.
- CVSS
- 25 / 40 · 6.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · EEF
- 6.3
- NVD has not scored this yet; the score shown is the CNA’s.
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- erlang erlang/otp17.0 and later · before 27.3.4
- erlang erlang/otp28.0 and later · before 28.5.0.4
- erlang erlang/otp29.0 and later · before 29.0.4
- erlang erts6.0 and later · before 15.2.7.11
- erlang erts16.0 and later · before 16.4.0.4
- erlang erts17.0 and later · before 17.0.4
Versions reported by the vendor
Affected version ranges reported by the assigning authority (EEF). Independent of NVD's CPE analysis and usually ahead of it.
Erlang OTP
- 6.0 and lateraffected · otpfixed in 17.0.4, 16.4.0.4, 15.2.7.11
- 17.0 and lateraffected · otpfixed in 29.0.4, 28.5.0.4, 27.3.4.15
- 07b8f441ca711f9812fad9e9115bab3c3aa92f79 and later · before 865d203e4a6a8f44179eced9e1428f9259e4a3bbaffected · git
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | erlang | all versions | — |
| Debian:13 | erlang | before 1:27.3.4.1+dfsg-1+deb13u3 | 1:27.3.4.1+dfsg-1+deb13u3 |
| Debian:14 | erlang | before 1:29.0.4+dfsg-1 | 1:29.0.4+dfsg-1 |
| openSUSE:Tumbleweed | erlang | before 28.5.0.4-1.1 | 28.5.0.4-1.1 |
| openSUSE:Tumbleweed | erlang27 | before 27.1.3-3.1 | 27.1.3-3.1 |
| Red Hat:hummingbird:1 | erlang27 | before 0:27.3.4.15-0.1.hum1 | 0:27.3.4.15-0.1.hum1 |
| SUSE:Linux Enterprise Module for Server Applications 15 SP7 | erlang | before 23.3.4.19-150300.3.39.1 | 23.3.4.19-150300.3.39.1 |
| SUSE:Linux Enterprise Module for Server Applications 15 SP7 | erlang26 | before 26.2.1-150300.7.28.1 | 26.2.1-150300.7.28.1 |
Same product
erlang: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-32433Erlang/OTP SSH Vulnerable to Pre-Authentication RCEKEV100Now
- CVE-2022-37026In Erlang/OTP before 23.3.4.15, 24.x before 24.3.4.2, and 25.x before 25.0.2, there is a Client Authentication Bypass in certain client-cert39Monitor
- CVE-2016-10253An issue was discovered in Erlang/OTP 18.x.39Monitor
- CVE-2026-55953TLS 1.2 and DTLS client accepts unoffered anonymous cipher suite, bypassing server authentication36Monitor
- CVE-2026-49759Stack buffer overflow in SCTP error cause parsing in inet_drv allows remote VM crash35Monitor
- CVE-2026-59251Denial of service via exponential certificate policy tree growth in path validation34Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Erlang OTP | 15.2.7.11 | Vendor (CNA) |
| Erlang OTP | 16.4.0.4 | Vendor (CNA) |
| Erlang OTP | 17.0.4 | Vendor (CNA) |
| Erlang OTP | 27.3.4.15 | Vendor (CNA) |
| Erlang OTP | 28.5.0.4 | Vendor (CNA) |
| Erlang OTP | 29.0.4 | Vendor (CNA) |
| Erlang OTP | 865d203e4a6a8f44179eced9e1428f9259e4a3bb | Vendor (CNA) |
| azl3 erlang 26.2.5.21-4 on Azure Linux 3.0 | 26.2.5.21-3 · CBL-Mariner Releases | Microsoft (MSRC) |
| debian:erlang | 1:27.3.4.1+dfsg-1+deb13u3 · Debian:13 | Package registry (OSV) |
| opensuse:erlang | 28.5.0.4-1.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| opensuse:erlang27 | 27.1.3-3.1 · openSUSE:Tumbleweed | Package registry (OSV) |
| red hat:erlang27 | 0:27.3.4.15-0.1.hum1 · Red Hat:hummingbird:1 | Package registry (OSV) |
| suse:erlang | 23.3.4.19-150300.3.39.1 · SUSE:Linux Enterprise Module for Server Applications 15 SP7 | Package registry (OSV) |
| suse:erlang26 | 26.2.1-150300.7.28.1 · SUSE:Linux Enterprise Module for Server Applications 15 SP7 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Ryan Moorefinder
- John Högbergremediation developer
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- Integrity
- Availability
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- X
Weakness class (CWE)
CWE-755 · Improper Handling of Exceptional ConditionsCVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- cna.erlef.org/cves/CVE-2026-42792.html
- github.com/erlang/otp/commit/865d203e4a6a8f44179eced9e1428f9259e4a3bb
- github.com/erlang/otp/security/advisories/GHSA-h6f3-hx58-xhj6
- osv.dev/vulnerability/EEF-CVE-2026-42792
- www.erlang.org/doc/system/versions.html#order-of-versions
Vendor advisories and official records. Exploit/PoC links are deliberately left out.