CVE-2026-12043: aws-c-http · Double Free
Affects aws-c-httpSource CVE Database V5
Not known to be exploited · CVSS 8.8 High · patch available : patch aws-c-http soon.
Data as of 30 Oct 2026, 06:59 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 12 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| AWSaws-c-http | Affected
| Fixed in– |
GitHubawslabs/aws-c-httppkg:github/awslabs/aws-c-httpOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Users should upgrade aws-c-http to version 0.11.0 or later, where this vulnerability is fixed. Since this is a library used by client applications, updating the dependency is the recommended remediation. There is no indication from the vendor advisory that any other mitigation or temporary workaround is available or required.
Description
CVE-2026-12043 is a high-severity vulnerability in the AWS Common Runtime aws-c-http library involving improper handling of HPACK dynamic table size updates. This flaw allows a remote server to cause memory corruption on a client application by sending a crafted sequence of HTTP/2 HEADERS frames, potentially leading to arbitrary code execution. The issue affects aws-c-http versions from 0.4.22 through 0.10.15 inclusive. A fix is available in version 0.11.0.