CVE-2026-55952
TLS 1.3 PSK handling crash in Erlang/OTP ssl
Is CVE-2026-55952 being exploited?
Not confirmed. CVE-2026-55952 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.48% probability of exploitation in the next 30 days.
How severe is CVE-2026-55952?
CVE-2026-55952 is rated High with a CVSS score of 8.2. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-55952?
Yes. A fix has been recorded for CVE-2026-55952. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-55952 affect?
CVE-2026-55952 affects Erlang/OTP ssl module (OTP versions 22.2–29.0.3; 28.5.0.3; 27.3.4.14). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-55952?
Upgrade Erlang/OTP to patched ssl (OTP ≥ 29.0.3; ssl ≥ 11.7.3)
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated attacker can crash TLS session ticket handler via crafted ClientHello; TLS 1.3 services become unusable until restart.
Immediate action required
- affected>= 9.5 and < *
- affected>= 22.2 and < *
- affected>= 339a279f02ce38a7b23010e56000613e19abb21f and < *
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.