mistral.rs before 0.9.5 Tool Call Injection via mistralrs-core Output Parsers
- Exploited
- No known exploitation
- Fix
- Fixed in 0.9.5
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 0.9.5.
- 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? →
- 9/100 · provisional
- 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
Mistral.rs versions before 0.9.5 have a flaw in their output parsers that lets an attacker add tool calls by planting delimiter tags, such as </tool_call>, in documents, web pages, or tool outputs that the model later quotes. The bug can be reached remotely without logging in, but it requires a user to take some action, and it can cause the model to make calls to its declared tools with attacker-chosen arguments.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original description
mistral.rs before 0.9.5 contains a delimiter injection vulnerability in mistralrs-core that allows attackers to inject tool calls by placing delimiter strings in text the model quotes. Attackers controlling documents, web pages or tool outputs can embed tags like </tool_call> to make qwen-xml, gemma4 or reasoning parsers return extra calls to declared tools with attacker-chosen arguments.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure7/25Reachable over the network without a login · Unknown: No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity2.3/10CVSS 2.3
- No patch0/5No signal
What would change the score
- Would score about 64 if added to CISA KEV
- Would score about 59 if CISA's SSVC rates exploitation active
- Would score about 24 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 0.9.5.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- EricLBuehler mistral.rs
fixed in 0.9.5
Evidence 6
- Advisory
- Patch
- Patch
- Repository
- Repository
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-124028
Is CVE-2026-124028 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
Which versions are affected by CVE-2026-124028?
mistral.rs: before 0.9.5.Source: cve.now feed data
How do I fix CVE-2026-124028?
Upgrade to a fixed version: 0.9.5.Source: cve.now feed data