GROBID: Unauthenticated `/api/modelTraining` Endpoint Allows Unbounded Thread Pool Creation (DoS)
Only GROBID 0.9.0 with the default configuration and its HTTP port reachable from an untrusted network is covered. The fix is in 0.9.1.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fixed in 0.9.1
- Who is exposed
- Default setups
Do first: Check every install: default setups are affected.
- Last modified
- FIRST's estimate of the chance attackers exploit it in the next 30 days, updated daily.What do these mean? →
- 0.35% · 28th percentile
- 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? →
- 30/100 · 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? →
- Default setups
- 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
GROBID, a machine learning tool for extracting information from scholarly documents, can be made to crash or stop responding through its model training endpoint, which needs no login. Remote attackers can repeatedly send requests that exhaust the server's thread capacity, denying service to legitimate users.
Read the original description
GROBID is machine learning software for extracting information from scholarly documents. Prior to 0.9.1, the unauthenticated /api/modelTraining endpoint calls GrobidRestProcessTraining.trainModel in GrobidRestProcessTraining.java, where each request creates Executors.newFixedThreadPool(1), submits a training task, and leaves the executor running. Repeated requests permanently retain JVM worker threads and can exhaust process or operating-system thread capacity, degrading or stopping request processing. This issue is fixed in version 0.9.1.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure22/25Default setups, reachable over the network without a login
- Reach?/20Unknown. No tracked technology or package matched
- Severity7.5/10CVSS 7.5
- No patch0/5No signal
What would change the score
- Would score about 70 if added to CISA KEV
- Would score about 65 if CISA's SSVC rates exploitation active
What to do
Check every install: default setups are affected.
Upgrade to a fixed version: 0.9.1.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- grobidOrg grobid
fixed in 0.9.1
Evidence 4
- Advisory
- Repository
- Repository
- Repository
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-123356
Is CVE-2026-123356 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?
The unauthenticated /api/modelTraining endpoint lets a remote sender trigger repeated POST requests that create threads without limit. This exhausts JVM and operating-system threads, which degrades and eventually halts request processing.Source: github.com
Which versions are affected by CVE-2026-123356?
grobid: before 0.9.1.Source: cve.now feed data
Am I affected, and how do I check?
The affected version is 0.9.0, in the default configuration with the service HTTP port reachable from an untrusted network. To check, look at the installed GROBID version and whether the service HTTP port can be reached from untrusted networks.Source: github.com
How do I fix CVE-2026-123356?
Upgrade GROBID to 0.9.1, which is the listed fixed version.Source: github.com