CVE-2026-77650
Malicious Rust crate enabling remote code execution during compilation.
Is CVE-2026-77650 being exploited?
Not confirmed. CVE-2026-77650 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.43% probability of exploitation in the next 30 days.
How severe is CVE-2026-77650?
CVE-2026-77650 is rated Critical with a CVSS score of 9.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-77650?
Yes. A fix has been recorded for CVE-2026-77650. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-77650 affect?
CVE-2026-77650 affects append-only-vec 0.1.9 (Rust crate), Rust projects depending on that crate, CI/CD/build agents, Developer workstations. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-77650?
Remove/update the crate, block build network egress, rebuild artifacts, and audit CI/dev machines.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Arbitrary code execution at build time via a rogue dependency that contacts a C2, compromising developer machines and CI/CD pipelines.
Immediate action required
- affected0.1.9
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.