CVE-2026-28810: Predictable DNS Transaction IDs Enable Cache Poisoning in Built-in Resolver
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.3%
Down from 0.4% on .
EPSS score, percentile 19.1 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 6.3 Medium
CVSS v4.0 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
- Which versions are affected?
Affected
- 3.0
- 17.0
Unaffected from 10.6.2; from 10.2.7.4; from 9.2.4.11; from 28.4.2; from 27.3.4.10; from 26.2.5.19
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Workaround (from the CVE record)
Install the Erlang nodes in a trusted network shielded from DNS reply spoofing by firewalls, and configure the inet_res resolver to only talk to trusted recursive name servers within that network.
Advisories and patches
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | 3.0 |
| Unaffected | from 10.6.2 |
| Unaffected | from 10.2.7.4 |
| Unaffected | from 9.2.4.11 |
Versions not listed are: unknown.
| Status | Versions |
|---|---|
| Affected | 17.0 |
| Unaffected | from 28.4.2 |
| Unaffected | from 27.3.4.10 |
| Unaffected | from 26.2.5.19 |
| Affected | 07b8f441ca71 |
| Unaffected | from 36f23c9d2cc5 |
| Unaffected | from dd15e8eb0354 |
| Unaffected | from b057a9d99501 |
Versions not listed are: unknown.
Versions the record lists as unaffected: 10.6.2, 10.2.7.4, 9.2.4.11, 28.4.2, 27.3.4.10, 26.2.5.19, 36f23c9d2cc54afe83671dd7343596d7972839a5, dd15e8eb03548c5e55e9915f0e91389ec6bad9fd.
Source: CVE List, as of . About the data.
About this vulnerability
Generation of Predictable Numbers or Identifiers vulnerability in Erlang/OTP kernel (inet_res, inet_db modules) allows DNS Cache Poisoning. The built-in DNS resolver (inet_res) uses a sequential, process-global 16-bit transaction ID for UDP queries and does not implement source port randomization. Response validation relies almost entirely on this ID, making DNS cache poisoning practical for an…
Summary: CVE record, as of .
- CISA has not added CVE-2026-28810 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 7 Apr 2026.
- The CVE record carries a CVSS v4.0 base score of 6.3 (Medium), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.3% (percentile 19.1), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation none, automatable no, technical impact partial.
- The credits in the CVE record name AISLE as finder.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
Predictable DNS Transaction IDs Enable Cache Poisoning in Built-in Resolver
Generation of Predictable Numbers or Identifiers vulnerability in Erlang/OTP kernel (inet_res, inet_db modules) allows DNS Cache Poisoning. The built-in DNS resolver (inet_res) uses a sequential, process-global 16-bit transaction ID for UDP queries and does not implement source port randomization. Response validation relies almost entirely on this ID, making DNS cache poisoning practical for an attacker who can observe one query or predict the next ID. This conflicts with RFC 5452 recommendations for mitigating forged DNS answers. inet_res is intended for use in trusted network environments and with trusted recursive resolvers. Earlier documentation did not clearly state this deployment assumption, which could lead users to deploy the resolver in environments where spoofed DNS responses are possible. This vulnerability is associated with program files lib/kernel/src/inet_db.erl and lib/kernel/src/inet_res.erl. This issue affects OTP from OTP 17.0 before OTP 28.4.2, OTP 27.3.4.10 and OTP 26.2.5.19, corresponding to kernel from 3.0 before 10.6.2, 10.2.7.4 and 9.2.4.11.
Source: CVE List, as of . About the data.
Weakness
CWE-340, 1 CAPEC
- CWE-340: Generation of Predictable Numbers or Identifiers
Attack patterns (CAPEC)
- CAPEC-142: DNS Cache Poisoning
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |
References
3
Known exploited Erlang vulnerabilities
- CVE-2025-32433: Erlang Erlang/OTP SSH Server Missing Authentication for Critical Function Vulnerability