CVE-2026-55687
HIGHESF-IDF: Stack-Based Out-of-Bounds Write in JPEG Decoder DQT Marker Parsing
Description
ESF-IDF is the Espressif Internet of Things (IOT) Development Framework. Versions 6.0.1, 5.5.4, 5.4.4, 5.3.5, and possibly prior contain an out-of-bounds write in jpeg_parse_dqt_marker() in components/esp_driver_jpeg/jpeg_parse_marker.c because the attacker-controlled DQT marker Tq nibble is used as an index into the qt_tbl array without validating that it is in the range 0..3, allowing malformed JPEG input to corrupt stack memory and reliably trigger a denial of service. This 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.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-55687 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-55687 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-55687. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-55687 in your dependencies?
O3 detects CVE-2026-55687 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.