CVE-2026-94300: Concurrent GSS-TSIG messages corrupt memory
Vulnerability summary
CVE-2026-94300 is a high (CVSS 8.1) vulnerability in isc bind 9. EPSS estimates a 0.95% chance of exploitation in the next 30 days, higher than 61.3% of scored vulnerabilities.
Severe, CVSS 8.1 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 3 · Related 2Timeline
- 21-10-2026PublishedVulnerability first disclosed.
- 22-10-2026Last modifiedVulnerability information updated.
Description
Replaying GSS-TSIG signed UDP messages can result in memory corruption in "`named`". An attacker who can capture a previously signed UDP message can replay it while the negotiated TSIG key is still valid. By also sending crafted queries to a zone the attacker controls, the attacker may potentially achieve remote code execution. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.29, 9.21.0 through 9.21.26, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.29-S1.
CVSS metrics
5 scores · 5 sources · 1 version- NVDNIST8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · AlpineEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated8.1HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.95%
Chance of exploitation in the next 30 days
Percentile
61%
Versus all other CVEs
30-day change
Change unavailable
Change unavailable
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-362Concurrent Execution using Shared Resource with Improper SynchronizationThe product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
- CWE-415Double FreeThe product calls free() twice on the same memory address.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Chainguard7 products
- bindAll versions (No fix recorded)
- bind-devAll versions (No fix recorded)
- bind-dnssec-rootAll versions (No fix recorded)
- bind-dnssec-toolsAll versions (No fix recorded)
- bind-libsAll versions (No fix recorded)
Wolfi7 products
- bindAll versions (No fix recorded)
- bind-devAll versions (No fix recorded)
- bind-dnssec-rootAll versions (No fix recorded)
- bind-dnssec-toolsAll versions (No fix recorded)
- bind-libsAll versions (No fix recorded)
Ubuntu3 products
- bind9All versions (No fix recorded) | < 1:9.18.39-0ubuntu0.22.04.8 | < 1:9.18.39-0ubuntu0.24.04.9 | < 1:9.20.24-1ubuntu3.1 | < 1:9.20.24-1ubuntu0.5
- bind9-libsAll versions (No fix recorded)
- isc-dhcpAll versions (No fix recorded)
Alpine1 product
- bind< 9.20.30-r0
Debian1 product
- bind9All versions (No fix recorded) | < 1:9.20.30-1~deb13u1 | < 1:9.20.30-1
Isc1 product
- bind 9≥ 9.11.0, ≤ 9.18.50 | ≥ 9.20.0, ≤ 9.20.29 | ≥ 9.21.0, ≤ 9.21.26 | ≥ 9.11.3-S1, ≤ 9.18.50-S1 | ≥ 9.20.9-S1, ≤ 9.20.29-S1
6 vendors · 20 products