TinyUSB 0.21.0 Out-of-Bounds Write via mtp_container_get_string()
Affects TinyUSB 0.21.0 and earlier builds that use the MTP device class. The checked facts do not list a vendor rating or a fixed version.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
- Exploited
- No known exploitation
- Fix
- Fix or patch referenced
- Who is exposed
- Specific setups only
Do first: Check whether your setup matches what the bug needs. The TinyUSB MTP device class is in use (src/class/mtp/mtp.h, mtp_container_get_string()). TinyUSB version 0.21.0 or earlier is affected.
- Exploitation0/40No signal
- Exposure5/25Specific setups only
- Reach?/20Reach: unknown (data gap). No tracked technology or package matched
- Severity8/10CVSS 7.0, total technical impact per CISA
- No patch0/5No signal
What would change the score
- Would score about 63 if added to CISA KEV
- Would score about 58 if CISA's SSVC rates exploitation active
- Would score about 23 if CISA's SSVC rates it automatable
CVE-2026-61495 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 7.0 (high) and affects TinyUSB; a fix or patch is referenced.
- 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- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean?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? →
- 13/100 · 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? →
- Specific setups only
- Fix
- Fix or patch referenced
- 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: none
- Automatable: no
- Technical impact: total
Summary
TinyUSB, a USB stack used in embedded devices, is affected when its MTP (Media Transfer Protocol) device class is enabled. A malicious USB host can send a specially crafted string that overwrites nearby memory on the device, which could allow code execution or crash the device.
Read the original description
TinyUSB through 0.21.0, fixed in commit e85c2b8, contains an out-of-bounds write vulnerability in the MTP device class helper mtp_container_get_string() in src/class/mtp/mtp.h that allows a malicious USB host to corrupt adjacent memory by supplying a crafted MTP string with an unbounded character count. Attackers can exploit the unchecked memcpy operation copying up to 510 bytes into a fixed-size destination buffer to achieve code execution or cause a denial of service on the TinyUSB MTP device.
What to do
Check whether your setup matches what the bug needs.
The TinyUSB MTP device class is in use (src/class/mtp/mtp.h, mtp_container_get_string()). TinyUSB version 0.21.0 or earlier is affected.Apply the patch listed under Evidence.
Timeline
- CVE published
- First seen by cve.now
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: total
- Record last updated
Affected versions
- hathach TinyUSB
through 0.21.0
Evidence 2
- Patch
- Link
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-61495
Is CVE-2026-61495 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?
A malicious USB host can write past the end of a buffer in mtp_container_get_string() in src/class/mtp/mtp.h, corrupting adjacent memory. The impact may be code execution or a denial of service on the TinyUSB MTP device.Source: vulncheck.com
Which versions are affected by CVE-2026-61495?
TinyUSB: through 0.21.0.Source: cve.now feed data
Am I affected, and how do I check?
TinyUSB 0.21.0 and earlier are affected, and only builds that use the MTP device class are relevant. To check, look at the TinyUSB version in your tree and whether the MTP class is included in your build.Source: vulncheck.com
How do I fix CVE-2026-61495?
The checked facts do not name a fixed version or a workaround. Check the TinyUSB release notes for a version later than 0.21.0 and upgrade to it once it is available.Source: vulncheck.com