Erlang/OTP Updates Fix TLS Authentication and Denial-of-Service Flaws
Tech GuruQuick Answer
The authority published GHSA-rgxr-4g4w-j875 for Erlang/OTP ssl, asn1, and ssh applications in supported OTP 27, 28, and 29 streams. The Erlang/OTP project fixed a TLS 1.3 server-authentication bypass, superlinear ASN.1 OID decoding during untrusted certificate parsing, and unbounded idle SSH channel allocation. The TLS workaround is to restrict affected clients to TLS 1.2 until patched; the other issues have no complete configuration workaround. Affected deployments should be matched to the authority's exact scope and moved to the supported fixed release.
Confirm Scope And Apply The Supported Fix
What to do now: Inventory Erlang/OTP ssl, asn1, and ssh applications in supported OTP 27, 28, and 29 streams, match the exact affected release or feature, apply the authority-supported fixed build or service remediation, validate the dependent workflow, and preserve evidence.
Last verified: 2026-09-22 UTC. Recheck the authoritative advisory and supported distribution channel before changing production.
Scope And Authority
| Product scope | Erlang/OTP ssl, asn1, and ssh applications in supported OTP 27, 28, and 29 streams |
|---|---|
| Advisory | GHSA-rgxr-4g4w-j875 / GHSA-qghx-23m5-r55m / GHSA-qhcm-px9c-rvfh |
| CVEs | CVE-2026-65634, CVE-2026-68956, CVE-2026-89422 |
| Authoritative release date | 2026-09-22 08:34:34 UTC |
| Authority revision date | 2026-09-22 08:38:50 UTC |
| Affected versions | OTP 22.2 and later for the TLS flaw, OTP 17 and later for ASN.1 decoding, and OTP 18.1.2 and later for SSH, below the branch-specific patched releases. |
| Fixed version | OTP 27.3.4.18, 28.5.0.7, or 29.1.1; ssl 11.2.12.13/11.6.0.6/11.7.7, asn1 5.3.4.3/5.4.3.1/5.5.2, and ssh 5.2.11.13/5.5.2.6/6.0.6 |
| CVSS base score | 7.1 / 8.2 / 9.3 (CVSS v4.0) |
| CVSS severity | High to Critical |
| Exploitation status | Not stated by the authority; no exploitation claim is inferred. |
What Changed
The Erlang/OTP project fixed a TLS 1.3 server-authentication bypass, superlinear ASN.1 OID decoding during untrusted certificate parsing, and unbounded idle SSH channel allocation. The TLS workaround is to restrict affected clients to TLS 1.2 until patched; the other issues have no complete configuration workaround.
What To Validate Now
- Inventory. Locate Erlang/OTP ssl, asn1, and ssh applications in supported OTP 27, 28, and 29 streams deployments, versions, enabled features, exposure paths, owners, and dependent services.
- Establish applicability. Compare each deployment with the authority's affected-version statement: OTP 22.2 and later for the TLS flaw, OTP 17 and later for ASN.1 decoding, and OTP 18.1.2 and later for SSH, below the branch-specific patched releases. Do not infer applicability from product family or severity alone.
- Remediate. Apply OTP 27.3.4.18, 28.5.0.7, or 29.1.1; ssl 11.2.12.13/11.6.0.6/11.7.7, asn1 5.3.4.3/5.4.3.1/5.5.2, and ssh 5.2.11.13/5.5.2.6/6.0.6 through the supported vendor or project channel, following the current advisory and change-control requirements.
- Validate. Confirm the resulting version or managed-service state, exercise representative functionality and recovery paths, monitor for regressions, and document exceptions.
- Retain evidence. Preserve asset and owner identifiers, the applicability decision, before-and-after versions, change approval, installation output, validation results, and any exception or rollback record.
Operational Cautions
Use the exact supported release stream and repository. Test dependencies, clusters, integrations, and rollback before broad deployment; a CVSS rating or reachable feature is not evidence of exploitation.
Evidence To Retain
- Exact product, release stream, package or application version, enabled feature, environment, and accountable owner.
- UTC timestamps, authority revision, approved change record, installer or package-manager output, and resulting version.
- Relevant logs and monitoring evidence, test results, exceptions, compensating controls, and rollback decisions.
Related TechGeeks Resources
Authoritative References
Correction policy: If the authority changes affected versions, fixed versions, severity, exploitation information, mitigations, or required action, TechGeeks will update this notice and its verification date.
