CVE-2026-23943
MEDIUMDescription
Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion. The SSH transport layer advertises legacy zlib compression by default and inflates attacker-controlled payloads pre-authentication without any size limit, enabling reliable memory exhaustion DoS. Two compression algorithms are affected: * zlib: Activates immediately after key exchange, enabling unauthenticated attacks * [email protected]: Activates post-authentication, enabling authenticated attacks Each SSH packet can decompress ~255 MB from 256 KB of wire data (1029:1 amplification ratio). Multiple packets can rapidly exhaust available memory, causing OOM kills in memory-constrained environments. This vulnerability is associated with program files lib/ssh/src/ssh_transport.erl and program routines ssh_transport:decompress/2, ssh_transport:handle_packet_part/4. This issue affects OTP from OTP 17.0 before OTP 28.4.1, OTP 27.3.4.9 and OTP 26.2.5.18, corresponding to ssh from 3.0.1 before 5.5.1, 5.2.11.6 and 5.1.4.14.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Exploit Intelligence
Moderate risk: more likely to be exploited than 47% of all known CVEs.
References
Related Vulnerabilities
Other CWE-409 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2026-49975 | High | 7.5 | 28% | - | Fix |
| CVE-2026-21441 | High | 7.5 | 2.7% | - | Fix |
| CVE-2024-43499 | High | 7.5 | 2.6% | - | Fix |
| CVE-2024-28180 | Medium | 4.3 | 2.0% | - | Fix |
| CVE-2017-16129 | Medium | 5.9 | 1.8% | - | Fix |
| CVE-2022-29225 | High | 7.5 | 1.5% | - | Fix |
Common questions
How do I fix CVE-2026-23943?
Upgrade erlang on debian 11 to 1:23.2.6+dfsg-1+deb11u4 or later.
Is CVE-2026-23943 being actively exploited?
Not that we know of. CVE-2026-23943 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.64% is the estimated probability that it will be exploited in the next 30 days. That is higher than 47% of all scored CVEs.
How severe is CVE-2026-23943?
CVE-2026-23943 has a CVSS v3 base score of 5.3, rated moderate. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-23943 affect?
Published advisories record a fix for erlang (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-23943
Markdown
[](https://tridentstack.com/cve/CVE-2026-23943)HTML
<a href="https://tridentstack.com/cve/CVE-2026-23943"><img src="https://tridentstack.com/cve/badge/CVE-2026-23943.svg" alt="CVE-2026-23943"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-24.