Issue summary: The 'openssl dgst' command-line tool silently truncates input
data to 16MB when using one-shot signing algorithms and reports success instead
of an error.
Impact summary: A user signing or verifying files larger than 16MB with
one-shot algorithms (such as Ed25519, Ed448, or ML-DSA) may believe the entire
file is authenticated while trailing data beyond 16MB remains unauthenticated.
When the 'openssl dgst' command is used with algorithms that only support
one-shot signing (Ed25519, Ed448, ML-DSA-44, ML-DSA-65, ML-DSA-87), the input
is buffered with a 16MB limit. If the input exceeds this limit, the tool
silently truncates to the first 16MB and continues without signaling an error,
contrary to what the documentation states. This creates an integrity gap where
trailing bytes can be modified without detection if both signing and
verification are performed using the same affected codepath.
The issue affects only the command-line tool behavior. Verifiers that process
the full message using library APIs will reject the signature, so the risk
primarily affects workflows that both sign and verify with the affected
'openssl dgst' command. Streaming digest algorithms for 'openssl dgst' and
library users are unaffected.
The FIPS modules in 3.5 and 3.6 are not affected by this issue, as the
command-line tools are outside the OpenSSL FIPS module boundary.
OpenSSL 3.5 and 3.6 are vulnerable to this issue.
OpenSSL 3.4, 3.3, 3.0, 1.1.1 and 1.0.2 are not affected by this issue.
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.
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