PatchSiren cyber security CVE debrief
CVE-2026-55687 espressif CVE debrief
The Espressif Internet of Things (IOT) Development Framework (ESF-IDF) versions 6.0.1, 5.5.4, 5.4.4, 5.3.5, and possibly prior contain an out-of-bounds write vulnerability in the jpeg_parse_dqt_marker() function. This issue allows an attacker to trigger a denial of service by providing malformed JPEG input, which can corrupt stack memory. The vulnerability has a high impact on the affected systems, and users should apply patches or mitigations to prevent potential denial-of-service attacks. The issue is caused by the use of an attacker-controlled DQT marker Tq nibble as an index into the qt_tbl array without proper validation.
- Vendor
- espressif
- Product
- esp-idf
- CVSS
- HIGH 7.5
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-10
- Original CVE updated
- 2026-07-10
- Advisory published
- 2026-07-10
- Advisory updated
- 2026-07-10
Who should care
Users of ESF-IDF versions 6.0.1, 5.5.4, 5.4.4, 5.3.5, and possibly prior should apply patches or mitigations to prevent potential denial-of-service attacks. The vulnerability has a high impact on the affected systems, and users should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
Technical summary
The vulnerability is caused by the use of an attacker-controlled DQT marker Tq nibble as an index into the qt_tbl array without proper validation. This can lead to an out-of-bounds write, allowing malformed JPEG input to corrupt stack memory and reliably trigger a denial of service. The issue is fixed in version 6.0.2 and is expected to be fixed in versions 5.5.5, 5.4.5, and 5.3.6. The vulnerability has a CVSS score of 7.5 and a severity of HIGH.
Defensive priority
High
Recommended defensive actions
- Apply patches or updates to ESF-IDF versions 6.0.1, 5.5.4, 5.4.4, 5.3.5, and possibly prior
- Implement input validation and sanitization for JPEG data
- Monitor for and respond to potential denial-of-service attacks
- Review compensating controls for exposed systems while remediation is scheduled and verified
- Check relevant monitoring, detection, and logs for exposed assets that need extra review
- Track exceptions, retest remediated assets, and close the item only after evidence is documented
- Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
Evidence notes
The CVE record was published on 2026-07-10T17:16:59.590Z and has not been modified since then. The NVD entry is currently Deferred. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity with the vendor. The issue is fixed in version 6.0.2 and is expected to be fixed in versions 5.5.5, 5.4.5, and 5.3.6. However, the CVE record does not provide detailed information about the vulnerability or the affected products.
Official resources
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-10T17:16:59.590Z and has not been modified since then.