How to Fix CVE-2026-43507: Prosody (Bundle Sibling)
By Sai Kiran Pandrala
Last verified: 2026-05-25
CVE-2026-43507 is a sibling vulnerability in the same vendor advisory as CVE-2026-43504. Applying the patched build named in the primary write-up closes this CVE as well.
| Severity | CVSS 5.3 - Medium |
|---|---|
| Actively exploited? | Not currently in CISA KEV |
| Affected | Same as the bundle - see CVE-2026-43504 |
| Fixed in | Same patched build as CVE-2026-43504 (See vendor advisory) |
| Type (CWE) | CWE-770: CWE-770 Allocation of Resources Without Limits or Throttling |
What's different about CVE-2026-43507?
An issue was discovered in Prosody before 0.12.6 and 1.0.0 through 13.0.0 before 13.0.5. A Denial of Service can occur via memory exhaustion caused by XML parsing resource amplification from unauthenticated connections.
The technical impact and remediation are identical to the primary CVE in the bundle. The same vendor patch closes both.
How to fix CVE-2026-43507
Apply the patched build per the primary write-up: How to Fix CVE-2026-43504.
The patch installation procedure, verification commands, and interim mitigations are documented there. Reusing one runbook keeps the rollout consistent across the bundle.
Frequently asked questions
Is CVE-2026-43507 fixed by the same patch as CVE-2026-43504?
Yes. CVE-2026-43507 ships in the same vendor advisory as CVE-2026-43504. Applying the patched build named in the primary write-up closes both.
What is the CVSS score for CVE-2026-43507?
The CVSS base score is 5.3 (Medium).
Is it being exploited?
It is not currently listed in CISA KEV.
References
- Official vendor advisory: https://prosody.im/security/advisory_735dd9d3/
- NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-43507
- CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
- Primary write-up: How to Fix CVE-2026-43504
*Part of the Prosody bundle. Full procedure at CVE-2026-43504.*