CVE-2026-27853: powerdns dnsdist Out-of-bounds Write
Vulnerability summary
CVE-2026-27853 is a high (CVSS 7.5) Out-of-bounds Write vulnerability in powerdns dnsdist. EPSS estimates a 1.50% chance of exploitation in the next 30 days, higher than 73.9% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 3 · Related 3Timeline
- 31-03-2026PublishedVulnerability first disclosed.
- 31-03-2026Last modifiedVulnerability information updated.
Description
An attacker might be able to trigger an out-of-bounds write by sending crafted DNS responses to a DNSdist using the DNSQuestion:changeName or DNSResponse:changeName methods in custom Lua code. In some cases the rewritten packet might become larger than the initial response and even exceed 65535 bytes, potentially leading to a crash resulting in denial of service.
CVSS metrics
4 scores · 4 sources · 1 version- CVE.orgCNA5.9MediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:HDiffers
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
1.50%
Chance of exploitation in the next 30 days
Percentile
74%
Versus all other CVEs
30-day change
+1.01 pp
From 0.49% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian1 product
- dnsdistAll versions (No fix recorded) | < 1.9.14-0+deb13u1 | < 2.0.3-1
Powerdns1 product
- dnsdist≥ 1.9.0, < 1.9.12 | ≥ 2.0.0, < 2.0.3
Ubuntu1 product
- dnsdistAll versions (No fix recorded)
3 vendors · 3 products
