CVE-2026-23943
- Source
- https://cve.org/CVERecord?id=CVE-2026-23943
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23943.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2026-23943
- Aliases
-
- EEF-CVE-2026-23943
- GHSA-c836-qprm-jw9r
- Downstream
- Related
- Published
- 2026-03-13T09:11:57.794Z
- Modified
- 2026-07-08T08:04:56.341023240Z
- Severity
-
- 6.9 (Medium) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N CVSS Calculator
- Summary
- Pre-auth SSH DoS via unbounded zlib inflate
- Details
-
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
- zlib@openssh.com: 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/sshtransport.erl and program routines sshtransport:decompress/2, sshtransport:handlepacket_part/4.
This issue affects OTP from OTP 17.0 until OTP 28.4.1, 27.3.4.9 and 26.2.5.18 corresponding to ssh from 3.0.1 until 5.5.1, 5.2.11.6 and 5.1.4.14.
- Database specific
{ "unresolved_ranges": [ { "source": "AFFECTED_FIELD", "extracted_events": [ { "introduced": "3.0.1" }, { "fixed": "*" }, { "introduced": "17.0" }, { "fixed": "*" }, { "introduced": "07b8f441ca711f9812fad9e9115bab3c3aa92f79" }, { "fixed": "*" } ] } ], "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23943.json", "cna_assigner": "EEF", "cwe_ids": [ "CWE-409" ] }- References
-
- https://cna.erlef.org/cves/CVE-2026-23943.html
- https://github.com
- https://osv.dev/vulnerability/EEF-CVE-2026-23943
- https://www.erlang.org/doc/system/versions.html#order-of-versions
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23943.json
- https://github.com/erlang/otp/security/advisories/GHSA-c836-qprm-jw9r
- https://nvd.nist.gov/vuln/detail/CVE-2026-23943
- https://github.com/erlang/otp/commit/0c1c04b191f6ab940e8fcfabce39eb5a8a6440a4
- https://github.com/erlang/otp/commit/43a87b949bdff12d629a8c34146711d9da93b1b1
- https://github.com/erlang/otp/commit/93073c3bd338c60cd2bae715ce6a1d4ffc1a8fd3
- https://github.com/erlang/otp
Affected packages
Git / github.com/erlang/otp
Affected ranges
- Type
- GIT
- Repo
- https://github.com/erlang/otp
- Events
-
IntroducedFixedIntroducedFixedIntroducedFixedFixedFixedFixed
- Database specific
{ "source": [ "CPE_RANGE", "REFERENCES" ], "cpe": "cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*", "extracted_events": [ { "introduced": "17.0" }, { "fixed": "26.2.5.18" }, { "introduced": "27.0" }, { "fixed": "27.3.4.9" }, { "introduced": "28.0" }, { "fixed": "28.4.1" } ] }