Skip to content
Fencer Vulns
low 3.7

CVE-2026-54891 json

Plaintext APPLICATION_DATA injected during TLS handshake delivered to client application post-handshake in ssl

published 2026-07-02 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-41415

cvss
3.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.1%
EPSS 0.1% chance of exploitation in 30 days, percentile 3%
public exploits
0
none known

Summary

Improper Enforcement of Message Integrity During Transmission in a Communication Channel vulnerability in Erlang/OTP ssl (tls_gen_connection module) allows a network-positioned attacker to inject unauthenticated plaintext that the TLS client application later treats as authenticated server data.

The function tls_gen_connection:handle_protocol_record/3 rejects APPLICATION_DATA records that arrive in pre-handshake states when the TLS endpoint acts as a server, but does not apply the same check when the endpoint acts as a client. A network-positioned attacker can send plaintext APPLICATION_DATA records to the client during the handshake. The records are buffered and, once the handshake completes successfully, delivered to the application as if they were authenticated post-handshake data. The attacker cannot observe the client's response or steer the connection, so the impact is limited to blind injection of unauthenticated bytes. The injection window is wider for TLS versions prior to TLS 1.3 than for TLS 1.3.

This vulnerability is associated with program file lib/ssl/src/tls_gen_connection.erl.

TLS 1.3 is affected starting with OTP 22.0, when TLS 1.3 support was added.

This issue affects OTP from OTP 17.0 before OTP 27.3.4.14, from OTP 28.0 before OTP 28.5.0.3, and from OTP 29.0 before OTP 29.0.3, corresponding to ssl from 5.3.4 before 11.2.12.10, from 11.3 before 11.6.0.3, and from 11.7 before 11.7.3. Whether OTP before OTP 17.0, corresponding to ssl before 5.3.4, is affected is unknown.

Patch / fix

  • Erlang OTP 11.2.12.10, 11.6.0.3, 11.7.3, 27.3.4.14, 28.5.0.3, 29.0.3
  • erlang Debian 13 1:27.3.4.1+dfsg-1+deb13u3
  • erlang Debian 14 1:29.0.3+dfsg-1

debian advisories DEBIAN-CVE-2026-54891

  • erlang Ubuntu 22.04 LTS 1:24.2.1+dfsg-1ubuntu0.8
  • erlang Ubuntu 24.04 LTS 1:25.3.2.8+dfsg-1ubuntu4.8
  • erlang Ubuntu 26.04 LTS 1:27.3.4.6+dfsg-1ubuntu0.2
  • erlang Ubuntu Pro 14.04 LTS 1:16.b.3-dfsg-1ubuntu2.2+esm3
  • erlang Ubuntu Pro 16.04 LTS 1:18.3-dfsg-1ubuntu3.1+esm4
  • erlang Ubuntu Pro 18.04 LTS 1:20.2.2+dfsg-1ubuntu2+esm4
  • erlang Ubuntu Pro 20.04 LTS 1:22.2.7+dfsg-1ubuntu0.5+esm3

ubuntu advisories UBUNTU-CVE-2026-54891

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • erlang27 hummingbird 1 27.3.4.17-1.hum1
  • erlang27-et hummingbird 1 27.3.4.17-1.hum1
  • erlang27-wx hummingbird 1 27.3.4.17-1.hum1
  • erlang27-ftp hummingbird 1 27.3.4.17-1.hum1
  • erlang27-ssh hummingbird 1 27.3.4.17-1.hum1
  • erlang27-ssl hummingbird 1 27.3.4.17-1.hum1
  • erlang27-asn1 hummingbird 1 27.3.4.17-1.hum1
  • erlang27-edoc hummingbird 1 27.3.4.17-1.hum1

red hat advisories RHSA-2026:63160

  • erlang SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 23.3.4.19-150300.3.39.1
  • erlang26 SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Server Applications 15 SP7 26.2.1-150300.7.28.1

suse advisories SUSE-SU-2026:3645-1SUSE-SU-2026:3579-1

  • erlang openSUSE Tumbleweed 28.5.0.4-1.1
  • erlang27 openSUSE Tumbleweed 27.1.3-3.1

opensuse advisories openSUSE-SU-2026:11559-1openSUSE-SU-2026:11560-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-54891 updated cvss 3.7

erlang: Erlang SSL: Unauthenticated data injection during TLS handshake

  • Red Hat OpenStack Platform 16.2 erlang, erlang-ssl, erlang-asn1, erlang-erts, erlang-hipe, erlang-sasl, +15 more Red Hat OpenStack Platform 17.1 erlang-ssl, erlang-asn1, erlang-erts, erlang-sasl, erlang-snmp, erlang-eldap, +13 more Red Hat OpenStack Platform 18.0 erlang
    affected: no fix available “Fix deferred”
  • Red Hat Hardened Images erlang27 27.3.4.17-1.hum1
    fixed: vendor fix RHSA-2026:63160

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
4 mo ago

Exploit prediction

0.14% chance of exploitation in the next 30 days, higher than 3% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CNA 4.0 6.3 CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/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 3.1 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Affected products

  • Erlang OTP

Classification

Weakness
  • CWE-924 Improper Enforcement of Message Integrity During Transmission in a Communication Channel

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.