FreeRDP before 3.32.2 Double Free in WinPR Kerberos retrieveSomeTgt
Affects FreeRDP servers before 3.32.2 that run Kerberos with a configured keytab and a default realm in krb5. No vendor rating is given. Fixed in 3.32.2.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- Proof of concept public, per CISA
- Fix
- Fixed in 3.32.2
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 3.32.2.
- Exploitation15/40CISA rates a proof of concept as public
- Exposure20/25No login or user action needed, CISA rates it automatable · Data gap: Advisories don't say whether default setups are affected
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity8.7/10CVSS 8.7
- No patch0/5No signal
What would change the score
- Would score about 74 if added to CISA KEV
- Would score about 69 if CISA's SSVC rates exploitation active
- Would score about 49 if advisories confirm default setups are exposed
CVE-2026-121956 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.7 (high) and affects FreeRDP; fixed in 3.32.2.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- 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? →
- 44/100 · 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
- Fix
- Fixed in 3.32.2
- 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
- Exploitation: poc
- Automatable: yes
- Technical impact: partial
Summary
FreeRDP versions before 3.32.2 have a double free bug in the WinPR Kerberos code that an attacker can reach remotely, without logging in, by sending a crafted NLA/CredSSP request. Successful exploitation crashes the server process by corrupting the heap.
Read the original description
FreeRDP before 3.32.2 contains a double free in the WinPR Kerberos SSPI retrieveSomeTgt function, which installs the krb5 default realm into a target principal that has an empty realm without taking ownership of it. Unauthenticated remote clients can send a crafted NLA/CredSSP u2u TGT request whose server-name component contains '@' to corrupt the heap and crash the server process.
What to do
Upgrade to a fixed version: 3.32.2.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: poc · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- FreeRDP FreeRDP
fixed in 3.32.2
Evidence 2
- Advisory
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-121956
Is CVE-2026-121956 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. CISA's SSVC assessment notes a proof of concept exists. No public exploit code is tracked.Source: cve.now feed data
What does this mean?
A heap double free in WinPR's Kerberos retrieveSomeTgt code corrupts allocator metadata in the server process and can crash it.Source: github.com
Which versions are affected by CVE-2026-121956?
FreeRDP: before 3.32.2.Source: cve.now feed data
Am I affected, and how do I check?
All FreeRDP versions before 3.32.2 are affected, but only when the server has Kerberos enabled with a configured keytab and a valid u2u sub-mechanism, and krb5 has a default realm set. Check the installed FreeRDP version and the server's Kerberos and krb5 configuration.Source: github.com
How do I fix CVE-2026-121956?
Upgrade FreeRDP to 3.32.2 or later, which contains the fix.Source: github.com