Security readout for executives and security teams
Plain-English summary
A malformed S/MIME encrypted message can crash GnuPG's agent component in versions before 2.5.17. The reported flaw is primarily a denial-of-service risk, but the source notes memory corruption that could potentially enable remote code execution.
Executive priority
Treat this as high priority for systems that decrypt S/MIME or CMS content. Patch planning should be prompt because the flaw is remotely reachable through crafted content and may exceed simple service disruption.
Technical view
CVE-2026-24881 is a stack-based buffer overflow in gpg-agent during CMS PKDECRYPT--kem=CMS handling when processing an oversized wrapped session key. The CVSS 3.1 score is 8.1 with network attack vector and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure is most likely where GnuPG before 2.5.17 processes CMS/S/MIME EnvelopedData messages. The bundle explicitly references GnuPG 2.5.13, but product-specific package impact should be confirmed against vendor advisories.
Exploitation context
The bundle does not cite CISA KEV listing or confirmed active exploitation. The CVE text says denial of service is easy to leverage and remote code execution may be possible because memory corruption occurs.
Researcher notes
The key uncertainty is exploitability beyond denial of service. Sources describe stack overflow and memory corruption, but do not provide confirmed exploitation, working exploit evidence, or complete downstream vendor impact in the prompt bundle.
Mitigation direction
- Upgrade GnuPG to 2.5.17 or a vendor-supported fixed package.
- Check Red Hat and upstream GnuPG guidance for distribution-specific impact.
- Limit automatic S/MIME decryption exposure where operationally feasible.
- Monitor vendor advisories for updated affected-version and backport information.
Validation and detection
- Inventory GnuPG and gpg-agent versions across mail and automation systems.
- Identify systems processing CMS/S/MIME EnvelopedData messages.
- Review logs for unusual gpg-agent crashes or restart loops.
- Confirm vendor package status using upstream and distribution advisories.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-121: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-24881 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H2.25.9mitreCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H2.25.9redhat-SADPVulnerability scoring details
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- ADP timelineredhat-SADP
Made public.
- CVE publishedCVE Program
The CVE record was published.
- ADP timelineredhat-SADP
Reported to Red Hat.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
- 2026-01-27T19:02:29.973Z: Reported to Red Hat.
- 2026-01-27T18:36:56.727Z: Made public.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.openwall.com/lists/oss-security/2026/01/27/8CVE reference, mitre
- https://dev.gnupg.org/T8044CVE reference, mitre
- https://access.redhat.com/security/cve/CVE-2026-24881CVE reference, redhat-SADP · vdb-entry, x_refsource_REDHAT
- RHBZ#2433480CVE reference, redhat-SADP · issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-24881.jsonCVE reference, redhat-SADP · x_sadp-csaf-vex
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Stack-based Buffer Overflow
Stack-based Buffer Overflow represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.