# CVE-2026-104592: libosmocore out-of-bounds read in CBSP decoder

Source: https://junglewise.ai/threats/cve-2026-104592-libosmocore-through-1-14-1-contains-an-out-of-bounds-read-in-the  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-26. Updated: 2026-10-26  
License: CC BY 4.0 with a link back

CVE-2026-104592 · Severity: info · Published 2026-10-26

libosmocore is a library for cellular mobile networks that implements the CBSP protocol for cell broadcast alerts. A remote attacker can send a malformed CBSP WRITE-REPLACE message that triggers a read beyond allocated memory bounds in the decoder, causing the application to crash and disrupting emergency alert delivery.

Technologies: [Osmocom Libosmocore](https://junglewise.ai/threats/technologies/libosmocore). Vendors: [Osmocom](https://junglewise.ai/threats/vendors/osmocom).

## Quick answers

**Is CVE-2026-104592 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-104592 being exploited in the wild.

**How severe is CVE-2026-104592?** Informational severity, published 26 October 2026.

**Which products and versions are affected?** Osmocom Libosmocore through 1.14.1.

**Is there a fix for CVE-2026-104592?** Yes: fixed in libosmocore 1.14.2 or later (fix committed as 1659b58). Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-104592 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-104592?** Check whether you run Osmocom Libosmocore at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in libosmocore 1.14.2 or later (fix committed as 1659b58)

## Technical details

The CBSP WRITE-REPLACE decoder in src/gsm/cbsp.c reads an 8-bit page count from untrusted network input and uses it directly as an array bound, allowing access beyond a 16-entry stack buffer. This out-of-bounds read occurs in cbsp_dec_write_repl() and can be triggered by any remote entity sending a crafted CBSP message without authentication. An attacker gains denial of service through application crash; memory disclosure is theoretically possible depending on adjacent stack content.

## Affected products

- osmocom libosmocore through 1.14.1

## Timeline

- 2026-10-26: disclosed

## References

- [https://gerrit.osmocom.org/c/libosmocore/+/43215](https://gerrit.osmocom.org/c/libosmocore/+/43215)
- [https://github.com/osmocom/libosmocore/commit/1659b5874223934d5586e3e96b7d59f653c90ea6](https://github.com/osmocom/libosmocore/commit/1659b5874223934d5586e3e96b7d59f653c90ea6)

## Related threats

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- [libosmocore out-of-bounds read in GSM 04.80 parser](https://junglewise.ai/threats/cve-2026-104596-libosmocore-through-1-14-1-contains-out-of-bounds-reads-in-the)
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- [libosmocore buffer overflow in osmo_iuup_compute_payload_crc()](https://junglewise.ai/threats/cve-2026-104591-libosmocore-through-1-14-1-contains-a-buffer-overflow-in-osmo)