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TI-2026-83330 Aliases CVE-2026-62298

NULL pointer dereference in asn1c OPEN TYPE decoding causes crash

Priority LOW 3CWE-476Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-476.

Summary

The asn1c ASN.1 compiler before 1.2.5 can dereference an unallocated member pointer while decoding OPEN TYPE members. This is a NULL pointer dereference (CWE-476) in the APER, BER, OER and UPER OPEN TYPE decoders, where a conditional null check does not stop the code from computing a value from the unallocated pointer. An attacker with low privileges over the network can crash the program that consumes the decoded data.

Written with Claude Haiku 5.5 from the sources below · 2026-10-31

Description from the CNA

mouse07410/asn1c is an ASN.1 compiler. Prior to 1.2.5, `OPEN TYPE` decoding can dereference an unallocated member pointer and crash the consuming program. `OPEN_TYPE_aper_get` in `OPEN_TYPE_aper.c`, `OPEN_TYPE_ber_get` in `OPEN_TYPE_ber.c`, `OPEN_TYPE_oer_get` in `OPEN_TYPE_oer.c`, and `OPEN_TYPE_uper_get` in `OPEN_TYPE_uper.c` share the pattern: a conditional null check on `*memb_ptr2` resets presence only when the member exists, but execution then unconditionally computes an inner value from that pointer and a member offset. If the `OPEN TYPE` member has not been allocated, the null-pointer arithmetic and subsequent read cause a segmentation fault. The advisory demonstrates UPER and APER crashes for `E2connectionUpdateAcknowledge`, notes that `E2AP` uses APER, and provides a BER reproducer; OER is also explicitly identified as affected. This issue is fixed in version 1.2.5.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00502 43rd percentileScored 2026-11-07
Fix Fixed asn1c (mouse07410): 1.2.5

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
mouse07410asn1cbefore 1.2.51.2.5Patch availableCNA
  • asn1c Vendormouse07410 Affected before 1.2.5 Fixed in 1.2.5 Patch available CNA

Remediation

Upgrade asn1c to version 1.2.5, which fixes this issue.

Written with Claude Haiku 5.5 from the sources below · 2026-10-31

  • Fix · CNA asn1c (mouse07410) Fixed in 1.2.5

Timeline

  1. 2026-10-30 Threatist record created from CVE-2026-62298
  2. 2026-10-30 CISA SSVC decision points changed

References

Other 4

  • TI-2026-33360 mouse07410/asn1c: 1-byte Heap Out-of-Bounds Read in `INTEGER_decode_oer` via Malformed OER Payload CVSS 3.1HIGH 8.2

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences