Erlang/OTP 29.1.2, 28.5.0.8 and 27.3.4.19 Fix TLS, X.509 and httpc CVEs, and 29.1.2 Also Fixes an erl_tar Infinite Loop
Three Erlang/OTP patch packages dated October 14, 2026 list four shared CVEs; 29.1.2 adds a fifth, a denial-of-service in erl_tar that also affects Hex and rebar3 copies.
Overview
The Erlang/OTP project published three patch packages on October 14, 2026: OTP 29.1.2, OTP 28.5.0.8 and OTP 27.3.4.19. Each README lists the same four CVEs: CVE-2026-105236, CVE-2026-42789, CVE-2026-48856 and CVE-2026-94200. The 29.1.2 README adds a fifth, CVE-2026-96596.
The four shared fixes
CVE-2026-94200 (ssl, TLS 1.3 client tickets). The project’s advisory rates it high, with a CVSS 4.0 score of 8.2. A malicious or man-in-the-middle TLS 1.3 server can poison a NewSessionTicket with a zero-length early_data extension. On the next automatic resumption the node-global tls_client_ticket_store crashes, and the advisory says the persistent poison plus the supervision setup can cascade into a node-wide ssl outage. The advisory’s workaround is to not enable automatic ticket handling with the option {session_tickets, auto}. Patched ssl versions are 11.7.8 (OTP 29.1.2), 11.6.0.7 (28.5.0.8) and 11.2.12.14 (27.3.4.19), according to the 29.1.2, 28.5.0.8 and 27.3.4.19 READMEs.
CVE-2026-105236 (ssl, TLS 1.2 session resumption). This one is rated medium with a CVSS 4.0 score of 6.3, per its advisory. A TLS server hosting several SNI names on one listener did not bind a cached session to the SNI name that created it. The advisory lists as prerequisites that at least two SNI names share a server certificate but use distinct client CAs, that TLS 1.2 is negotiated, and that session reuse is not disabled. It says TLS 1.3 is not affected. Workarounds it lists are separate listen sockets per trust domain, {reuse_sessions, false}, or TLS 1.3. The 29.1.2 README adds that a listener’s derived reuse_sessions default is no longer carried into an SNI virtual service that switches to verify_peer, so such a service must enable reuse_sessions explicitly.
CVE-2026-42789 (public_key, X.509 path validation). The advisory, published May 27, 2026, rates it high at CVSS 4.0 7.0. It describes a non-CA certificate being accepted as an intermediate issuer, which enables chain forgery. The advisory says the issue was “mostly fixed” in OTP 29.0.1, 28.5.0.1, 27.3.4.12 and 26.2.5.21, and that the gap for legacy version 1 or 2 certificates was closed by an amended fix. The 29.1.2 README for public_key-1.21.8 says: “This closes the version-1 path left uncovered by the earlier CVE-2026-42789 fix.”
CVE-2026-48856 (inets, httpc redirects). The advisory, published June 10, 2026, rates it high at CVSS 4.0 7.1. The httpc client forwarded Authorization and proxy-authorization headers to cross-origin redirect targets, and autoredirect defaults to true. The advisory says the issue was partially fixed in OTP 29.0.2, 28.5.0.2 and 27.3.4.13, and that credentials supplied in the userinfo component of a request URI were still sent to the redirect target. It states that gap “is now closed” in the new releases.
The extra fix in 29.1.2
CVE-2026-96596 is an infinite loop in the erl_tar module, rated medium at CVSS 4.0 5.9. According to the advisory, a crafted GNU sparse member makes extraction loop forever, and a 2048-byte archive keeps the extracting process and one scheduler busy until the process is killed. The advisory lists OTP 29.0 and later as affected, with 29.1.2 (stdlib 8.1.1) as the fix, and says OTP 28 is not affected.
The same advisory notes that hex_core ships its own copy of the code as hex_erl_tar, with Hex and rebar3 shipping prefixed copies (mix_hex_erl_tar and r3_hex_erl_tar). Those copies are affected on any OTP version, so an application on OTP 28 can be affected if it extracts archives through an affected hex_core, Hex or rebar3. The advisory’s workaround is passing {chunks, N} together with {max_size, N} to erl_tar:extract/2, or extracting with the memory option, which is not affected.
Other changes in 29.1.2
The 29.1.2 README flags one potential incompatibility in ssh-6.0.7: when the max_channels limit is reached for a port-forwarding channel, the SSH daemon now refuses the individual channel and keeps the connection alive instead of terminating the whole connection. It also lists a fix for very slow compilation of a function with thousands of clauses. The 28.5.0.8 and 27.3.4.19 READMEs also contain a section on potential incompatibilities.
What We Don’t Know
The sources reviewed are the project’s own release notes and advisories. They do not report any exploitation of these flaws in the wild, and no independent assessment of the severity ratings was reviewed. Whether OTP releases older than those named in the advisories receive fixes is not stated in the material cited here.