OpenAM before 16.1.4 Unauthenticated DoS via Unbounded Java Deserialisation
Affects OpenAM releases up to and including 16.1.3 that expose endpoints accepting serialized Java data. Fixed in 16.1.4.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 16.1.4
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 16.1.4.
- Published
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 26/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
OpenAM before 16.1.4 contains a denial of service vulnerability that allows unauthenticated attackers to exhaust server resources by sending serialized Java data without size or structure limits. Attackers can send small crafted requests to remote SDK endpoints, classic login pages, or the administration console to block authentication, session validation and policy decisions.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed, reachable over the network without a login · Unknown: Advisories don't say whether default setups are affected
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.7/10CVSS 8.7
- No patch0/5No signal
What would change the score
- Would score about 71 if added to CISA KEV
- Would score about 66 if CISA's SSVC rates exploitation active
- Would score about 31 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 16.1.4.
Workaround: Restrict network access to the legacy remote SDK endpoints at the reverse proxy or firewall, restrict the administration console to administrators' networks, and limit request size and rate
Timeline
- CVE published
- First seen by cve.now
Affected versions
- OpenIdentityPlatform OpenAM
fixed in 16.1.4
Evidence 2
- Advisory
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-123543
Is CVE-2026-123543 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
Several OpenAM endpoints accept serialized Java data from requests, and unbounded deserialization lets a few small unauthenticated requests exhaust the server's CPU or memory. This can block authentication, session validation and policy decisions.Source: github.com
Which versions are affected by CVE-2026-123543?
OpenAM: before 16.1.4.Source: cve.now feed data
Am I affected, and how do I check?
All OpenAM releases up to and including 16.1.3 are affected where reachable endpoints accept serialized Java data: remote SDK interfaces, classic login pages, or the administration console. To check, look at the installed OpenAM version and whether those endpoints are enabled and reachable.Source: github.com
How do I fix CVE-2026-123543?
Upgrade to OpenAM 16.1.4, which contains the fix.Source: github.com