CVE-2026-58471
GNU Wget 1.25.0 Heap Buffer Overflow via convert_fname() in url.c
Description
GNU Wget through 1.25.0, fixed in commit c2640fe, contains a heap buffer overflow vulnerability in the convert_fname() function within src/url.c that allows remote attackers to trigger memory corruption through a server-supplied filename requiring character set conversion. When the output buffer is too small during iconv E2BIG reallocation, the reallocation logic miscalculates the remaining space, leading to a heap buffer overflow that can be exploited via a maliciously crafted server response.
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-2026-58471 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-2026-58471 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-2026-58471. 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-2026-58471 in your dependencies?
O3 detects CVE-2026-58471 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.