Issue summary: If an application using the SSL_CIPHER_find() function in
a QUIC protocol client or server receives an unknown cipher suite from
the peer, a NULL dereference occurs.
Impact summary: A NULL pointer dereference leads to abnormal termination of
the running process causing Denial of Service.
Some applications call SSL_CIPHER_find() from the client_hello_cb callback
on the cipher ID received from the peer. If this is done with an SSL object
implementing the QUIC protocol, NULL pointer dereference will happen if
the examined cipher ID is unknown or unsupported.
As it is not very common to call this function in applications using the QUIC
protocol and the worst outcome is Denial of Service, the issue was assessed
as Low severity.
The vulnerable code was introduced in the 3.2 version with the addition
of the QUIC protocol support.
The FIPS modules in 3.6, 3.5, 3.4 and 3.3 are not affected by this issue,
as the QUIC implementation is outside the OpenSSL FIPS module boundary.
OpenSSL 3.6, 3.5, 3.4 and 3.3 are vulnerable to this issue.
OpenSSL 3.0, 1.1.1 and 1.0.2 are not affected by this issue.
What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)
The EG score (5.9): severity, escalated by confirmed exploitation. This CVE's 5.9 is its impact severity (EG Severity), not escalated.
- EG Severity
- 5.9 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
- EG Likelihood
- 0.8% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-25). FIRST's exploitation probability, not an EchelonGraph model.
- Confirmed exploitation
- None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
- EG Priority
- SSVC Track at medium mission impactTrack at every mission impact level.CISA BOD 26-04: 60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.
SSVC (CISA's decision table, applied by EchelonGraph)Track at every mission impact level.
A fix is available. Apply it within your standard update timelines.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table
BOD 26-04 (CISA's remediation timeline, Table 1)60 days if the affected system is publicly exposed; Fix on system upgrade if it is not.
The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it