Security readout for executives and security teams
Plain-English summary
CVE-2026-21897 affects NASA CryptoLib before 1.4.3, a library used to secure spacecraft-to-ground communications with CCSDS SDLS-EP. A bounds-checking error can write past an internal array, potentially corrupting configuration state. The issue is rated high and is patched in version 1.4.3.
Executive priority
Treat as a high-priority update for affected space communication software. Urgency depends on whether CryptoLib is deployed in operational systems and whether relevant configuration inputs are exposed to network-originated data.
Technical view
Crypto_Config_Add_Gvcid_Managed_Parameters checks gvcid_counter > GVCID_MAN_PARAM_SIZE, allowing an off-by-one write beyond gvcid_managed_parameters_array[250]. The adjacent gvcid_counter can be overwritten, potentially disrupting parameter registration or lookup logic. CVSS 3.1 is 7.3: network attack vector, low complexity, no privileges, no user interaction, with low confidentiality, integrity, and availability impact.
Likely exposure
Exposure is likely limited to organizations using NASA CryptoLib before 1.4.3, especially in cFS-related spacecraft or ground-station communication stacks. The sources do not identify downstream products or deployments.
Exploitation context
The CVE record rates the issue as network-reachable with no privileges or user interaction required. CISA KEV is not indicated, and the provided sources do not report active exploitation or public weaponization.
Researcher notes
Evidence identifies an out-of-bounds write caused by an insufficient counter check in Crypto_Config_Add_Gvcid_Managed_Parameters. Public sources confirm the fix in 1.4.3 but do not provide broader exploitability details, affected downstream integrations, or active exploitation evidence.
Mitigation direction
- Upgrade NASA CryptoLib to version 1.4.3 or later.
- Review vendor advisory and release notes for implementation-specific guidance.
- Inventory systems using CryptoLib in flight or ground communication software.
- Prioritize environments where untrusted inputs can reach CryptoLib configuration paths.
Validation and detection
- Confirm deployed CryptoLib versions are 1.4.3 or later.
- Search source and build manifests for embedded CryptoLib copies.
- Verify no maintained branch still builds CryptoLib versions before 1.4.3.
- Review tests covering GVCID managed-parameter boundary conditions.
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
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Open ATT&CK lookupCVE-2026-21897 mapping review
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Open ATT&CK lookup- Severity
- High
- CVSS
- 7.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
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.
CVSS vector scores
1 official scoreWe 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:L/PR:N/UI:N/S:U/C:L/I:L/A:L3.93.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.3HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/nasa/CryptoLib/security/advisories/GHSA-9x7j-gx23-7m5rCVE reference · x_refsource_CONFIRM
- https://github.com/nasa/CryptoLib/releases/tag/v1.4.3CVE reference · x_refsource_MISC
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.
Out-of-bounds Write
Out-of-bounds Write represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.